diff --git a/src/Fantomas.Tests/ClassTests.fs b/src/Fantomas.Tests/ClassTests.fs
index 150e63f4c1..dba72264d7 100644
--- a/src/Fantomas.Tests/ClassTests.fs
+++ b/src/Fantomas.Tests/ClassTests.fs
@@ -32,14 +32,14 @@ module Heap
 
 type Heap<'T when 'T: comparison> =
     class
-        new : capacity: int -> Heap<'T>
-        member Clear : unit -> unit
-        member ExtractMin : unit -> 'T
-        member Insert : k: 'T -> unit
-        member IsEmpty : unit -> bool
-        member PeekMin : unit -> 'T
-        override ToString : unit -> string
-        member Count : int
+        new: capacity: int -> Heap<'T>
+        member Clear: unit -> unit
+        member ExtractMin: unit -> 'T
+        member Insert: k: 'T -> unit
+        member IsEmpty: unit -> bool
+        member PeekMin: unit -> 'T
+        override ToString: unit -> string
+        member Count: int
     end
 """
 
@@ -65,19 +65,19 @@ type Class7<'T when 'T : (new : unit -> 'T)>() =
     |> should
         equal
         """
-type Class4<'T when 'T: (static member staticMethod1 : unit -> 'T)> =
+type Class4<'T when 'T: (static member staticMethod1: unit -> 'T)> =
     class
     end
 
-type Class5<'T when 'T: (member Method1 : 'T -> int)> =
+type Class5<'T when 'T: (member Method1: 'T -> int)> =
     class
     end
 
-type Class6<'T when 'T: (member Property1 : int)> =
+type Class6<'T when 'T: (member Property1: int)> =
     class
     end
 
-type Class7<'T when 'T: (new : unit -> 'T)>() =
+type Class7<'T when 'T: (new: unit -> 'T)>() =
     member val Field = new 'T()
 """
 
@@ -124,15 +124,15 @@ type Shape2D(x0: float, y0: float) =
         with get () = y
         and set yval = y <- yval
 
-    abstract Area : float
-    abstract Perimeter : float
-    abstract Name : string
+    abstract Area: float
+    abstract Perimeter: float
+    abstract Name: string
 
     member this.Move dx dy =
         x <- x + dx
         y <- y + dy
 
-    abstract member Rotate : float -> unit
+    abstract member Rotate: float -> unit
     default this.Rotate(angle) = rotAngle <- rotAngle + angle
 """
 
@@ -156,13 +156,13 @@ type A =
         equal
         """
 type A =
-    abstract B : ?p1: (float * int) -> unit
-    abstract C : ?p1: float * int -> unit
-    abstract D : ?p1: (int -> int) -> unit
-    abstract E : ?p1: float -> unit
-    abstract F : ?p1: float * ?p2: float -> unit
-    abstract G : p1: float * ?p2: float -> unit
-    abstract H : float * ?p2: float -> unit
+    abstract B: ?p1: (float * int) -> unit
+    abstract C: ?p1: float * int -> unit
+    abstract D: ?p1: (int -> int) -> unit
+    abstract E: ?p1: float -> unit
+    abstract F: ?p1: float * ?p2: float -> unit
+    abstract G: p1: float * ?p2: float -> unit
+    abstract H: float * ?p2: float -> unit
 """
 
 [<Test>]
@@ -615,9 +615,9 @@ let ``no extra new line before abstract member with attribute, 586`` () =
 type A =
 
     [<EmitConstructor>]
-    abstract Create : Unit -> A
+    abstract Create: Unit -> A
 
-    abstract b : Unit -> Unit
+    abstract b: Unit -> Unit
 """
 
 [<Test>]
@@ -627,10 +627,10 @@ let ``no extra new line between abstract members with attribute, 586`` () =
 type A =
 
     [<Emit("a")>]
-    abstract a : Unit -> string
+    abstract a: Unit -> string
 
     [<Emit("b")>]
-    abstract b : Unit -> string
+    abstract b: Unit -> string
 """
 
 [<Test>]
@@ -780,7 +780,7 @@ type Foo =
 module Example
 
 type Foo =
-    abstract member bar : int
+    abstract member bar: int
 """
 
 [<Test>]
@@ -830,9 +830,9 @@ type ISingleExpressionValue<'p, 'o, 'v when 'p :> IProperty and 'o :> IOperator
         """
 type ISingleExpressionValue<'p, 'o, 'v when 'p :> IProperty and 'o :> IOperator and 'p: equality and 'o: equality and 'v: equality>
     () =
-    abstract Property : 'p
-    abstract Operator : 'o
-    abstract Value : 'v
+    abstract Property: 'p
+    abstract Operator: 'o
+    abstract Value: 'v
 """
 
 [<Test>]
diff --git a/src/Fantomas.Tests/CommentTests.fs b/src/Fantomas.Tests/CommentTests.fs
index 6adcdf6954..d8d204080c 100644
--- a/src/Fantomas.Tests/CommentTests.fs
+++ b/src/Fantomas.Tests/CommentTests.fs
@@ -1070,12 +1070,12 @@ type IExports =
         """
 [<AllowNullLiteral>]
 type IExports =
-    abstract DataSet : DataSetStatic
-    abstract DataView : DataViewStatic
-    abstract Graph2d : Graph2dStatic
-    abstract Timeline : TimelineStatic
+    abstract DataSet: DataSetStatic
+    abstract DataView: DataViewStatic
+    abstract Graph2d: Graph2dStatic
+    abstract Timeline: TimelineStatic
     // abstract Timeline: TimelineStaticStatic
-    abstract Network : NetworkStatic
+    abstract Network: NetworkStatic
 
 // type [<AllowNullLiteral>] MomentConstructor1 =
 //     [<Emit "$0($1...)">] abstract Invoke: ?inp: MomentInput * ?format: MomentFormatSpecification * ?strict: bool -> Moment
diff --git a/src/Fantomas.Tests/FormatAstTests.fs b/src/Fantomas.Tests/FormatAstTests.fs
index 0dfcb5dd51..3a1536c0da 100644
--- a/src/Fantomas.Tests/FormatAstTests.fs
+++ b/src/Fantomas.Tests/FormatAstTests.fs
@@ -91,7 +91,7 @@ type Foo =
         equal
         """[<AbstractClass>]
 type Foo =
-    abstract foo : int
+    abstract foo: int
     override __.foo = 1"""
 
 [<Test>]
@@ -107,7 +107,7 @@ type Foo =
         equal
         """[<AbstractClass>]
 type Foo =
-    abstract foo : int
+    abstract foo: int
     default __.foo = 1"""
 
 [<Test>]
@@ -123,7 +123,7 @@ type Foo =
         equal
         """[<AbstractClass>]
 type Foo =
-    abstract foo : int
+    abstract foo: int
     override __.foo = 1"""
 
 [<Test>]
diff --git a/src/Fantomas.Tests/FunctionDefinitionTests.fs b/src/Fantomas.Tests/FunctionDefinitionTests.fs
index a2e590df65..095659c28e 100644
--- a/src/Fantomas.Tests/FunctionDefinitionTests.fs
+++ b/src/Fantomas.Tests/FunctionDefinitionTests.fs
@@ -219,9 +219,9 @@ let inline heterogenousAdd(value1 : ^T when (^T or ^U) : (static member (+) : ^T
     |> should
         equal
         """
-let inline add (value1: ^T when ^T: (static member (+) : ^T * ^T -> ^T), value2: ^T) = value1 + value2
+let inline add (value1: ^T when ^T: (static member (+): ^T * ^T -> ^T), value2: ^T) = value1 + value2
 
-let inline heterogenousAdd (value1: ^T when (^T or ^U): (static member (+) : ^T * ^U -> ^T), value2: ^U) =
+let inline heterogenousAdd (value1: ^T when (^T or ^U): (static member (+): ^T * ^U -> ^T), value2: ^U) =
     value1 + value2
 """
 
@@ -448,8 +448,8 @@ let inline implicit< ^a,^b when ^a : (static member op_Implicit : ^b -> ^a)> arg
     |> should
         equal
         """
-let inline implicit< ^a, ^b when ^a: (static member op_Implicit : ^b -> ^a)> arg =
-    (^a: (static member op_Implicit : ^b -> ^a) arg)
+let inline implicit< ^a, ^b when ^a: (static member op_Implicit: ^b -> ^a)> arg =
+    (^a: (static member op_Implicit: ^b -> ^a) arg)
 """
 
 [<Test>]
@@ -491,7 +491,7 @@ let ``don't create redundant parentheses outside trait calls`` () =
     |> should
         equal
         """
-let f (arg: 'T) = (^T: (member Value : string) arg)
+let f (arg: 'T) = (^T: (member Value: string) arg)
 """
 
 [<Test>]
@@ -934,7 +934,7 @@ let inline deserialize< ^a when ( ^a or FromJsonDefaults) : (static member FromJ
     |> should
         equal
         """
-let inline deserialize< ^a when ^a: (static member FromJson : ^a -> Json< ^a >)> json =
+let inline deserialize< ^a when ^a: (static member FromJson: ^a -> Json< ^a >)> json =
     json |> Json.parse |> Json.deserialize< ^a>
 """
 
diff --git a/src/Fantomas.Tests/InterfaceTests.fs b/src/Fantomas.Tests/InterfaceTests.fs
index 72c17cfb43..47cc936dea 100644
--- a/src/Fantomas.Tests/InterfaceTests.fs
+++ b/src/Fantomas.Tests/InterfaceTests.fs
@@ -26,7 +26,7 @@ type Interface3 =
         equal
         """
 type IPrintable =
-    abstract member Print : unit -> unit
+    abstract member Print: unit -> unit
 
 type SomeClass1(x: int, y: float) =
     interface IPrintable with
@@ -35,7 +35,7 @@ type SomeClass1(x: int, y: float) =
 type Interface3 =
     inherit Interface1
     inherit Interface2
-    abstract member Method3 : int -> int
+    abstract member Method3: int -> int
 """
 
 [<Test>]
@@ -135,7 +135,7 @@ let ``should keep named arguments on abstract members`` () =
     |> should
         equal
         """type IThing =
-    abstract Foo : name: string * age: int -> bool
+    abstract Foo: name: string * age: int -> bool
 """
 
 [<Test>]
@@ -149,7 +149,7 @@ let ``should not skip 'with get()' in indexers`` () =
     |> should
         equal
         """type Interface =
-    abstract Item : int -> char with get
+    abstract Item: int -> char with get
 """
 
 [<Test>]
@@ -202,10 +202,10 @@ type MyLogInteface() =
         equal
         """
 type LogInterface =
-    abstract member Print : string -> unit
-    abstract member GetLogFile : string -> string
-    abstract member Info : unit -> unit
-    abstract member Version : unit -> unit
+    abstract member Print: string -> unit
+    abstract member GetLogFile: string -> string
+    abstract member Info: unit -> unit
+    abstract member Version: unit -> unit
 
 type MyLogInteface() =
     interface LogInterface with
@@ -234,7 +234,7 @@ type IArgParserTemplate =
         """/// Interface that must be implemented by all Argu template types
 type IArgParserTemplate =
     /// returns a usage string for every union case
-    abstract Usage : string
+    abstract Usage: string
 """
 
 [<Test>]
@@ -273,7 +273,7 @@ type Test =
         equal
         """
 type Test =
-    abstract RunJobs :
+    abstract RunJobs:
         folder: string
         * ?jobs: string
         * ?ctm: string
@@ -319,8 +319,8 @@ type IMyInterface =
         equal
         """
 type IMyInterface =
-    abstract MyProp : bool with get, set
-    abstract MyMethod : unit -> unit
+    abstract MyProp: bool with get, set
+    abstract MyMethod: unit -> unit
 """
 
 [<Test>]
diff --git a/src/Fantomas.Tests/ModuleTests.fs b/src/Fantomas.Tests/ModuleTests.fs
index 62242dca49..54d16dcf81 100644
--- a/src/Fantomas.Tests/ModuleTests.fs
+++ b/src/Fantomas.Tests/ModuleTests.fs
@@ -167,15 +167,15 @@ end"""
         """
 module Utils
 
-val turnTracingOn : unit -> unit
-val turnTracingOff : unit -> unit
-val isTraced : unit -> bool
+val turnTracingOn: unit -> unit
+val turnTracingOff: unit -> unit
+val isTraced: unit -> bool
 
 module Random =
-    val exponential : mean: float -> float
-    val nextInt : max: int -> int
-    val nextInt64 : max: int64 -> int64
-    val next : max: float -> float
+    val exponential: mean: float -> float
+    val nextInt: max: int -> int
+    val nextInt64: max: int64 -> int64
+    val next: max: float -> float
 """
 
 [<Test>]
@@ -703,7 +703,7 @@ namespace Test
 module App =
     type Msg = B of C
 
-    val a : string
+    val a: string
 """
 
 [<Test>]
diff --git a/src/Fantomas.Tests/NewlineBetweenTypeDefinitionAndMembersTests.fs b/src/Fantomas.Tests/NewlineBetweenTypeDefinitionAndMembersTests.fs
index 6b77bd479e..9ebbacdf56 100644
--- a/src/Fantomas.Tests/NewlineBetweenTypeDefinitionAndMembersTests.fs
+++ b/src/Fantomas.Tests/NewlineBetweenTypeDefinitionAndMembersTests.fs
@@ -185,7 +185,7 @@ type Range =
       To: float
       Name: string }
 
-    member Length : unit -> int
+    member Length: unit -> int
 """
 
 [<Test>]
@@ -211,7 +211,7 @@ type Color =
     | Green
     | Blue
 
-    member ToInt : unit -> int
+    member ToInt: unit -> int
 """
 
 [<Test>]
@@ -237,7 +237,7 @@ type Color =
     | Green = 1
     | Blue = 2
 
-    member ToInt : unit -> int
+    member ToInt: unit -> int
 """
 
 [<Test>]
@@ -257,7 +257,7 @@ namespace Signature
 
 type HttpContext with
 
-    member QueryString : unit -> string
+    member QueryString: unit -> string
 """
 
 [<Test>]
@@ -306,7 +306,7 @@ type MyRecord =
       Street: string
       Number: int }
 
-    member Score : unit -> int
+    member Score: unit -> int
 
 type MyRecord =
     { SomeField: int }
@@ -318,7 +318,7 @@ type Color =
     | Green = 1
     | Blue = 2
 
-    member ToInt : unit -> int
+    member ToInt: unit -> int
 """
 
 [<Test>]
diff --git a/src/Fantomas.Tests/NumberOfItemsRecordTests.fs b/src/Fantomas.Tests/NumberOfItemsRecordTests.fs
index d45a4b1f7e..151b120adc 100644
--- a/src/Fantomas.Tests/NumberOfItemsRecordTests.fs
+++ b/src/Fantomas.Tests/NumberOfItemsRecordTests.fs
@@ -595,7 +595,7 @@ type MyRecord =
       Bar: string
       Street: string
       Number: int }
-    member Score : unit -> int
+    member Score: unit -> int
 """
 
 
diff --git a/src/Fantomas.Tests/RecordTests.fs b/src/Fantomas.Tests/RecordTests.fs
index 8e323953ed..3fa57bb720 100644
--- a/src/Fantomas.Tests/RecordTests.fs
+++ b/src/Fantomas.Tests/RecordTests.fs
@@ -87,25 +87,25 @@ type Element =
     interface INode
 
     /// Constructs an new empty Element.
-    static member Create : name: string * ?uri: string -> Element
+    static member Create: name: string * ?uri: string -> Element
 
     /// Replaces the children.
-    static member WithChildren : children: #seq<#INode> -> self: Element -> Element
+    static member WithChildren: children: #seq<#INode> -> self: Element -> Element
 
     /// Replaces the children.
-    static member (-) : self: Element * children: #seq<#INode> -> Element
+    static member (-): self: Element * children: #seq<#INode> -> Element
 
     /// Replaces the attributes.
-    static member WithAttributes : attrs: #seq<string * string> -> self: Element -> Element
+    static member WithAttributes: attrs: #seq<string * string> -> self: Element -> Element
 
     /// Replaces the attributes.
-    static member (+) : self: Element * attrs: #seq<string * string> -> Element
+    static member (+): self: Element * attrs: #seq<string * string> -> Element
 
     /// Replaces the children with a single text node.
-    static member WithText : text: string -> self: Element -> Element
+    static member WithText: text: string -> self: Element -> Element
 
     /// Replaces the children with a single text node.
-    static member (--) : self: Element * text: string -> Element
+    static member (--): self: Element * text: string -> Element
 """
 
 [<Test>]
@@ -840,7 +840,7 @@ open System
 module Test =
     type ISomething =
         inherit IDisposable
-        abstract DoTheThing : string -> unit
+        abstract DoTheThing: string -> unit
 
     let test (something: IDisposable) (somethingElse: IDisposable) =
         { new ISomething with
@@ -1419,7 +1419,7 @@ module Foo =
             { ModeratelyLongName: int }
 
     type private Bang =
-        abstract Baz : int
+        abstract Baz: int
 """
 
 [<Test>]
diff --git a/src/Fantomas.Tests/SignatureTests.fs b/src/Fantomas.Tests/SignatureTests.fs
index 4d00b4f8e7..40491bb2b3 100644
--- a/src/Fantomas.Tests/SignatureTests.fs
+++ b/src/Fantomas.Tests/SignatureTests.fs
@@ -122,7 +122,7 @@ type A () =
         equal
         """
 type IA =
-    abstract F : (unit -> Option<'T>) -> Option<'T>
+    abstract F: (unit -> Option<'T>) -> Option<'T>
 
 type A() =
     interface IA with
@@ -148,9 +148,9 @@ type C =
 namespace TupleType
 
 type C =
-    member P1 : int * string
+    member P1: int * string
     /// def
-    member P2 : int
+    member P2: int
 """
 
 [<Test>]
@@ -168,7 +168,7 @@ val GetHashCodeTainted : (Tainted<'T> -> int) when 'T : equality
         """
 module Tainted
 
-val GetHashCodeTainted : (Tainted<'T> -> int) when 'T: equality
+val GetHashCodeTainted: (Tainted<'T> -> int) when 'T: equality
 """
 
 [<Test>]
@@ -188,7 +188,7 @@ type Test =
 module Test
 
 type Test =
-    static member internal FormatAroundCursorAsync : fileName: string -> unit
+    static member internal FormatAroundCursorAsync: fileName: string -> unit
 """
 
 [<Test>]
@@ -304,25 +304,25 @@ module Teq =
     /// Order isn't important
     /// a = b => b = a
     /// If you always do this followed by a cast, you may as well just use castFrom
-    val symmetry : Teq<'a, 'b> -> Teq<'b, 'a>
+    val symmetry: Teq<'a, 'b> -> Teq<'b, 'a>
 
     /// Let's compose two type-equalities: a = b && b = c => a = c
-    val transitivity : Teq<'a, 'b> -> Teq<'b, 'c> -> Teq<'a, 'c>
+    val transitivity: Teq<'a, 'b> -> Teq<'b, 'c> -> Teq<'a, 'c>
 
     /// Converts an 'a to a 'b
-    val cast : Teq<'a, 'b> -> ('a -> 'b)
+    val cast: Teq<'a, 'b> -> ('a -> 'b)
 
     /// Converts an 'a to a 'b
     /// Alias for cast
-    val castTo : Teq<'a, 'b> -> ('a -> 'b)
+    val castTo: Teq<'a, 'b> -> ('a -> 'b)
 
     /// Converts a 'b to an 'a
     /// Equivalent to symmetry >> cast, but more efficient
-    val castFrom : Teq<'a, 'b> -> ('b -> 'a)
+    val castFrom: Teq<'a, 'b> -> ('b -> 'a)
 
     /// Utility function to map an object of one type using a mapping function
     /// for a different type when we have a type equality between the two types
-    val mapAs : Teq<'a, 'b> -> ('b -> 'b) -> 'a -> 'a
+    val mapAs: Teq<'a, 'b> -> ('b -> 'b) -> 'a -> 'a
 
     /// The Cong module (short for congruence) contains functions that
     /// allow you safely transform Teqs into other Teqs that logically follow.
@@ -426,25 +426,25 @@ module Teq =
     /// Order isn't important
     /// a = b => b = a
     /// If you always do this followed by a cast, you may as well just use castFrom
-    val symmetry : Teq<'a, 'b> -> Teq<'b, 'a>
+    val symmetry: Teq<'a, 'b> -> Teq<'b, 'a>
 
     /// Let's compose two type-equalities: a = b && b = c => a = c
-    val transitivity : Teq<'a, 'b> -> Teq<'b, 'c> -> Teq<'a, 'c>
+    val transitivity: Teq<'a, 'b> -> Teq<'b, 'c> -> Teq<'a, 'c>
 
     /// Converts an 'a to a 'b
-    val cast : Teq<'a, 'b> -> ('a -> 'b)
+    val cast: Teq<'a, 'b> -> ('a -> 'b)
 
     /// Converts an 'a to a 'b
     /// Alias for cast
-    val castTo : Teq<'a, 'b> -> ('a -> 'b)
+    val castTo: Teq<'a, 'b> -> ('a -> 'b)
 
     /// Converts a 'b to an 'a
     /// Equivalent to symmetry >> cast, but more efficient
-    val castFrom : Teq<'a, 'b> -> ('b -> 'a)
+    val castFrom: Teq<'a, 'b> -> ('b -> 'a)
 
     /// Utility function to map an object of one type using a mapping function
     /// for a different type when we have a type equality between the two types
-    val mapAs : Teq<'a, 'b> -> ('b -> 'b) -> 'a -> 'a
+    val mapAs: Teq<'a, 'b> -> ('b -> 'b) -> 'a -> 'a
 
     /// The Cong module (short for congruence) contains functions that
     /// allow you safely transform Teqs into other Teqs that logically follow.
@@ -544,10 +544,10 @@ type T with
 namespace ExtensionParts
 
 type T =
-    new : unit -> T
+    new: unit -> T
 
 type T with
-    member Foo : int
+    member Foo: int
 """
 
 [<Test>]
@@ -584,7 +584,7 @@ open FSharp.Compiler.SourceCodeServices
 [<Sealed>]
 type CodeFormatter =
     /// Parse a source string using given config
-    static member ParseAsync :
+    static member ParseAsync:
         fileName: string * source: SourceOrigin * parsingOptions: FSharpParsingOptions * checker: FSharpChecker ->
         Async<(ParsedInput * string list) array>
 """
@@ -660,7 +660,7 @@ type internal Blah =
 namespace Foo
 
 type internal Blah =
-    abstract Baz : unit
+    abstract Baz: unit
 """
 
 [<Test>]
@@ -721,8 +721,8 @@ module Foo =
 namespace Blah
 
 module Foo =
-    val inline sum : ('a -> ^value) -> 'a Foo -> ^value
-        when ^value: (static member (+) : ^value * ^value -> ^value) and ^value: (static member Zero : ^value)
+    val inline sum: ('a -> ^value) -> 'a Foo -> ^value
+        when ^value: (static member (+): ^value * ^value -> ^value) and ^value: (static member Zero: ^value)
 """
 
 [<Test>]
@@ -878,7 +878,7 @@ module Some_module
 
 type foo = bool
 
-val bar : bool
+val bar: bool
 """
 
 [<Test>]
@@ -981,20 +981,20 @@ module Example
 module Foo =
     module Bar =
         type t = bool
-        val lol : unit -> bool
+        val lol: unit -> bool
 
     type t = int
-    val lmao : unit -> bool
+    val lmao: unit -> bool
 
 module Foo2 =
     module Bar =
         type t = bool
 
-        val lol : unit -> bool
+        val lol: unit -> bool
 
     type t = int
 
-    val lmao : unit -> bool
+    val lmao: unit -> bool
 """
 
 [<Test>]
@@ -1023,7 +1023,7 @@ type t1 = bool
 [<SomeAttribute>]
 type t2 = bool
 
-val foo : bool
+val foo: bool
 """
 
 [<Test>]
@@ -1163,7 +1163,7 @@ namespace Baz
 
 [<Sealed>]
 type Foo =
-    member inline Return : 'a -> Baz<'a>
+    member inline Return: 'a -> Baz<'a>
 """
 
 [<Test>]
@@ -1186,7 +1186,7 @@ namespace Baz
 
 [<Sealed>]
 type Foo =
-    member inline private Return : 'a -> Baz<'a>
+    member inline private Return: 'a -> Baz<'a>
 """
 
 [<Test>]
@@ -1210,12 +1210,12 @@ type C =
         """
 namespace Foo
 
-val blah : int
+val blah: int
 
 type C =
-    member P1 : int * string
+    member P1: int * string
     /// def
-    member P2 : int
+    member P2: int
 """
 
 [<Test>]
@@ -1234,7 +1234,7 @@ val create : something_really_long : unit -> another_really_long_thing : unit ->
         """
 namespace Bug
 
-val create :
+val create:
   something_really_long: unit ->
   another_really_long_thing: unit ->
   and_another_to_make_the_line_long_enough: unit ->
@@ -1350,7 +1350,7 @@ module Bar =
 
     [<Obsolete "">]
     ///
-    val f : unit -> unit
+    val f: unit -> unit
 """
 
 [<Test>]
@@ -1428,7 +1428,7 @@ val inline  internal u_tup4 : unpickler<'T2> -> unpickler<'T3> -> unpickler<'T4>
 module internal FSharp.Compiler.TypedTreePickle
 
 /// Deserialize a tuple
-val inline internal u_tup4 :
+val inline internal u_tup4:
     unpickler<'T2> -> unpickler<'T3> -> unpickler<'T4> -> unpickler<'T5> -> unpickler<'T2 * 'T3 * 'T4 * 'T5>
 """
 
@@ -1514,7 +1514,7 @@ and [<CustomEquality>] Bang =
             LongNameBarBarBarBarBarBarBar: int
         }
     ///
-    override GetHashCode : unit -> int
+    override GetHashCode: unit -> int
 """
 
 [<Test>]
@@ -1599,5 +1599,5 @@ type Foo =
     private
         { Bar: int
           Qux: string }
-    static member Baz : int
+    static member Baz: int
 """
diff --git a/src/Fantomas.Tests/SpecialConstructsTests.fs b/src/Fantomas.Tests/SpecialConstructsTests.fs
index 73c0479659..49664a1532 100644
--- a/src/Fantomas.Tests/SpecialConstructsTests.fs
+++ b/src/Fantomas.Tests/SpecialConstructsTests.fs
@@ -37,7 +37,7 @@ x.G[].TryFind 3
         equal
         """
 type F =
-    abstract G : int list -> Map<int,int>
+    abstract G: int list -> Map<int,int>
 
 let x: F =
     {new F with
diff --git a/src/Fantomas.Tests/TypeDeclarationTests.fs b/src/Fantomas.Tests/TypeDeclarationTests.fs
index 5c3a6c1abb..8c7c8f790f 100644
--- a/src/Fantomas.Tests/TypeDeclarationTests.fs
+++ b/src/Fantomas.Tests/TypeDeclarationTests.fs
@@ -237,7 +237,7 @@ let ``abstract and override keywords`` () =
         """
 type MyClassBase1() =
     let mutable z = 0
-    abstract member Function1 : int -> int
+    abstract member Function1: int -> int
 
     default u.Function1(a: int) =
         z <- z + a
@@ -1005,7 +1005,7 @@ type ILogger =
         equal
         """
 type ILogger =
-    abstract DebugFormat : format: String * [<ParamArray>] args: Object [] -> unit
+    abstract DebugFormat: format: String * [<ParamArray>] args: Object [] -> unit
 """
 
 [<Test>]
@@ -1022,8 +1022,8 @@ type A =
         equal
         """
 type A =
-    abstract member M : int -> (int -> unit)
-    abstract member M : float -> int
+    abstract member M: int -> (int -> unit)
+    abstract member M: float -> int
 """
 
 [<Test>]
@@ -1040,8 +1040,8 @@ type A =
         equal
         """
 type A =
-    abstract member M : (int -> int) -> unit
-    abstract member M : float -> int
+    abstract member M: (int -> int) -> unit
+    abstract member M: float -> int
 """
 
 [<Test>]
@@ -1058,7 +1058,7 @@ type Entity() =
         equal
         """
 type Entity() =
-    abstract Id : int with get, set
+    abstract Id: int with get, set
     override val Id = 0 with get, set
 """
 
@@ -1317,10 +1317,10 @@ type Graph2dOptions =
         """
 [<AllowNullLiteral>]
 type Graph2dOptions =
-    abstract zoomMin : float option with get, set
+    abstract zoomMin: float option with get, set
     // abstract moment: MomentConstructor option with get, set
-    abstract maxHeight : HeightWidthType option with get, set
-    abstract zIndex : float option with get, set
+    abstract maxHeight: HeightWidthType option with get, set
+    abstract zIndex: float option with get, set
 """
 
 [<Test>]
@@ -1408,7 +1408,7 @@ type internal Blah =
 namespace Foo
 
 type internal Blah =
-    abstract Baz : unit
+    abstract Baz: unit
 """
 
 [<Test>]
@@ -1786,11 +1786,11 @@ type DataGroup =
 [<AllowNullLiteral>]
 type SubGroupStackOptions =
     [<Emit "$0[$1]{{=$2}}">]
-    abstract Item : name: string -> bool with get, set
+    abstract Item: name: string -> bool with get, set
 
 [<AllowNullLiteral>]
 type DataGroup =
-    abstract className : string option with get, set
+    abstract className: string option with get, set
 """
 
 [<Test>]
@@ -1814,7 +1814,7 @@ let foo bar = zero
 [<AllowNullLiteral>]
 type SubGroupStackOptions =
     [<Emit "$0[$1]{{=$2}}">]
-    abstract Item : name: string -> bool with get, set
+    abstract Item: name: string -> bool with get, set
 
 [<AllowNullLiteral>]
 let foo bar = zero
@@ -1859,7 +1859,7 @@ type TimelineOptionsGroupEditableType = U2<bool, TimelineGroupEditableOption>
 [<AllowNullLiteral>]
 type TimelineOptionsGroupCallbackFunction =
     [<Emit "$0($1...)">]
-    abstract Invoke : group: TimelineGroup * callback: (TimelineGroup option -> unit) -> unit
+    abstract Invoke: group: TimelineGroup * callback: (TimelineGroup option -> unit) -> unit
 
 type TimelineOptionsGroupEditableType = U2<bool, TimelineGroupEditableOption>
 """
@@ -1884,7 +1884,7 @@ let myBinding a = 7
 [<AllowNullLiteral>]
 type TimelineOptionsGroupCallbackFunction =
     [<Emit "$0($1...)">]
-    abstract Invoke : group: TimelineGroup * callback: (TimelineGroup option -> unit) -> unit
+    abstract Invoke: group: TimelineGroup * callback: (TimelineGroup option -> unit) -> unit
 
 let myBinding a = 7
 """
diff --git a/src/Fantomas/CodePrinter.fs b/src/Fantomas/CodePrinter.fs
index 352fd0ba66..729f203414 100644
--- a/src/Fantomas/CodePrinter.fs
+++ b/src/Fantomas/CodePrinter.fs
@@ -872,10 +872,10 @@ and genVal astContext (Val (ats, px, ao, s, identRange, t, vi, isInline, _) as n
         match node with
         | ValSpfn (_, _, synValTyparDecls, _, _, _, _, _, _, _, range) -> range, synValTyparDecls
 
-    let genericParams =
+    let genericParams, hasGenerics =
         match synValTyparDecls with
-        | SynValTyparDecls ([], _, _) -> sepNone
-        | SynValTyparDecls (tpd, _, cst) -> genTypeParamPostfix astContext tpd cst
+        | SynValTyparDecls ([], _, _) -> sepNone, false
+        | SynValTyparDecls (tpd, _, cst) -> genTypeParamPostfix astContext tpd cst, true
 
     let (FunType namedArgs) = (t, vi)
 
@@ -887,7 +887,7 @@ and genVal astContext (Val (ats, px, ao, s, identRange, t, vi, isInline, _) as n
         -- s
         +> genericParams
         |> genTriviaFor Ident_ identRange)
-    +> sepColonWithSpacesFixed
+    +> ifElse hasGenerics sepColonWithSpacesFixed sepColon
     +> ifElse
         (List.isNotEmpty namedArgs)
         (autoIndentAndNlnIfExpressionExceedsPageWidth (genTypeList astContext namedArgs))
@@ -4052,6 +4052,8 @@ and genMemberSig astContext node =
             | TFun _ -> true
             | _ -> false
 
+        let hasGenerics = not tds.IsEmpty
+
         genPreXmlDoc px
         +> genAttributes astContext ats
         +> genMemberFlagsForMemberBinding
@@ -4063,7 +4065,7 @@ and genMemberSig astContext node =
         +> opt sepSpace ao genAccess
         +> ifElse (s = "``new``") (!- "new") (!-s)
         +> genTypeParamPostfix astContext tds tcs
-        +> sepColonWithSpacesFixed
+        +> ifElse hasGenerics sepColonWithSpacesFixed sepColon
         +> ifElse
             (List.isNotEmpty namedArgs)
             (autoIndentAndNlnIfExpressionExceedsPageWidth (genTypeList astContext namedArgs))
@@ -4784,12 +4786,13 @@ and genMemberDefn astContext node =
                 | None -> sprintf "abstract %s" s
             |> fun s -> !- s ctx
 
+        let hasGenerics = not tds.IsEmpty
         genPreXmlDoc px
         +> genAttributes astContext ats
         +> opt sepSpace ao genAccess
         +> genAbstractMemberKeyword
         +> genTypeParamPostfix astContext tds tcs
-        +> sepColonWithSpacesFixed
+        +> ifElse hasGenerics sepColonWithSpacesFixed sepColon
         +> autoIndentAndNlnIfExpressionExceedsPageWidth (genTypeList astContext namedArgs)
         -- genPropertyKind (not isFunctionProperty) mk
         +> autoIndentAndNlnIfExpressionExceedsPageWidth (genConstraints astContext t vi)