diff --git a/src/fsharp/CompilerDiagnostics.fs b/src/fsharp/CompilerDiagnostics.fs
index d368392468a..bda44aac036 100644
--- a/src/fsharp/CompilerDiagnostics.fs
+++ b/src/fsharp/CompilerDiagnostics.fs
@@ -377,7 +377,8 @@ let IsWarningOrInfoEnabled (err, severity) n level specificWarnOn =
     | 3517 -> false // optFailedToInlineSuggestedValue - off by default
     | 3388 -> false // tcSubsumptionImplicitConversionUsed - off by default
     | 3389 -> false // tcBuiltInImplicitConversionUsed - off by default
-    | 3390 -> false // tcImplicitConversionUsedForMethodArg - off by default
+    | 3390 -> false // xmlDocBadlyFormed - off by default
+    | 3395 -> false // tcImplicitConversionUsedForMethodArg - off by default
     | _ -> 
         (severity = FSharpDiagnosticSeverity.Info) ||
         (severity = FSharpDiagnosticSeverity.Warning && level >= GetWarningLevel err)
diff --git a/src/fsharp/FSComp.txt b/src/fsharp/FSComp.txt
index acad18382fd..a0446b9d35d 100644
--- a/src/fsharp/FSComp.txt
+++ b/src/fsharp/FSComp.txt
@@ -1594,7 +1594,6 @@ forFormatInvalidForInterpolated4,"Interpolated strings used as type IFormattable
 3387,tcAmbiguousImplicitConversion,"This expression has type '%s' and is only made compatible with type '%s' through an ambiguous implicit conversion. Consider using an explicit call to 'op_Implicit'. The applicable implicit conversions are:%s"
 3388,tcSubsumptionImplicitConversionUsed,"This expression implicitly converts type '%s' to type '%s'. See https://aka.ms/fsharp-implicit-convs."
 3389,tcBuiltInImplicitConversionUsed,"This expression uses a built-in implicit conversion to convert type '%s' to type '%s'. See https://aka.ms/fsharp-implicit-convs."
-3390,tcImplicitConversionUsedForMethodArg,"This expression uses the implicit conversion '%s' to convert type '%s' to type '%s'."
 3391,tcImplicitConversionUsedForNonMethodArg,"This expression uses the implicit conversion '%s' to convert type '%s' to type '%s'. See https://aka.ms/fsharp-implicit-convs. This warning may be disabled using '#nowarn \"3391\"."
 #3501   "This construct is not supported by your version of the F# compiler" CompilerMessage(ExperimentalAttributeMessages.NotSupportedYet, 3501, IsError=true)
 3390,xmlDocBadlyFormed,"This XML comment is invalid: '%s'"
@@ -1604,10 +1603,11 @@ forFormatInvalidForInterpolated4,"Interpolated strings used as type IFormattable
 3390,xmlDocDuplicateParameter,"This XML comment is invalid: multiple documentation entries for parameter '%s'"
 3390,xmlDocUnresolvedCrossReference,"This XML comment is invalid: unresolved cross-reference '%s'"
 3390,xmlDocMissingParameter,"This XML comment is incomplete: no documentation for parameter '%s'"
-3391,tcLiteralAttributeCannotUseActivePattern,"A [<Literal>] declaration cannot use an active pattern for its identifier"
 3392,containerDeprecated,"The 'AssemblyKeyNameAttribute' has been deprecated. Use 'AssemblyKeyFileAttribute' instead."
 3393,containerSigningUnsupportedOnThisPlatform,"Key container signing is not supported on this platform."
 3394,parsNewExprMemberAccess,"This member access is ambiguous. Please use parentheses around the object creation, e.g. '(new SomeType(args)).MemberName'"
+3395,tcImplicitConversionUsedForMethodArg,"This expression uses the implicit conversion '%s' to convert type '%s' to type '%s'."
+3396,tcLiteralAttributeCannotUseActivePattern,"A [<Literal>] declaration cannot use an active pattern for its identifier"
 3401,ilxgenInvalidConstructInStateMachineDuringCodegen,"The resumable code construct '%s' may only be used in inlined code protected by 'if __useResumableCode then ...' and the overall composition must form valid resumable code."
 3402,tcInvalidResumableConstruct,"The construct '%s' may only be used in valid resumable code."
 3501,tcResumableCodeFunctionMustBeInline,"Invalid resumable code. Any method of function accepting or returning resumable code must be marked 'inline'"
diff --git a/src/fsharp/FSharp.Compiler.Service/FSharp.Compiler.Service.fsproj b/src/fsharp/FSharp.Compiler.Service/FSharp.Compiler.Service.fsproj
index 36a323cc231..ae388ec4d33 100644
--- a/src/fsharp/FSharp.Compiler.Service/FSharp.Compiler.Service.fsproj
+++ b/src/fsharp/FSharp.Compiler.Service/FSharp.Compiler.Service.fsproj
@@ -15,7 +15,13 @@
     <DefineConstants>$(DefineConstants);COMPILER</DefineConstants>
     <DefineConstants>$(DefineConstants);ENABLE_MONO_SUPPORT</DefineConstants>
     <DefineConstants Condition="'$(FSHARPCORE_USE_PACKAGE)' == 'true'">$(DefineConstants);USE_SHIPPED_FSCORE</DefineConstants>
-    <OtherFlags>$(OtherFlags) /warnon:3218 /warnon:1182 /warnon:3390 --extraoptimizationloops:1 --times</OtherFlags>
+    <OtherFlags>$(OtherFlags) --extraoptimizationloops:1 --times</OtherFlags>
+    <!-- 1182: Unused variables -->
+    <OtherFlags>$(OtherFlags) --warnon:1182</OtherFlags>
+    <!-- 3218: ArgumentsInSigAndImplMismatch -->
+    <OtherFlags>$(OtherFlags) --warnon:3218</OtherFlags>
+    <!-- 3390: xmlDocBadlyFormed -->
+    <OtherFlags>$(OtherFlags) --warnon:3390</OtherFlags>
     <Tailcalls>true</Tailcalls> <!-- .tail annotations always emitted for this binary, even in debug mode -->
     <FsYaccOutputFolder>$(IntermediateOutputPath)$(TargetFramework)\</FsYaccOutputFolder>
     <FsLexOutputFolder>$(IntermediateOutputPath)$(TargetFramework)\</FsLexOutputFolder>
diff --git a/tests/FSharp.Compiler.ComponentTests/ErrorMessages/InvalidLiteralTests.fs b/tests/FSharp.Compiler.ComponentTests/ErrorMessages/InvalidLiteralTests.fs
index bf6630b4313..a72d93c2743 100644
--- a/tests/FSharp.Compiler.ComponentTests/ErrorMessages/InvalidLiteralTests.fs
+++ b/tests/FSharp.Compiler.ComponentTests/ErrorMessages/InvalidLiteralTests.fs
@@ -15,4 +15,4 @@ let [<Literal>] (A x) = 1
         """
         |> typecheck
         |> shouldFail
-        |> withSingleDiagnostic (Error 3391, Line 3, Col 5, Line 3, Col 22, "A [<Literal>] declaration cannot use an active pattern for its identifier")
+        |> withSingleDiagnostic (Error 3396, Line 3, Col 5, Line 3, Col 22, "A [<Literal>] declaration cannot use an active pattern for its identifier")
diff --git a/tests/fsharp/core/auto-widen/preview/test.bsl b/tests/fsharp/core/auto-widen/preview/test.bsl
index 947390ac100..94ad06d8bc0 100644
--- a/tests/fsharp/core/auto-widen/preview/test.bsl
+++ b/tests/fsharp/core/auto-widen/preview/test.bsl
@@ -133,7 +133,7 @@ test.fsx(128,22,128,23): typecheck error FS3389: This expression uses a built-in
 
 test.fsx(128,22,128,23): typecheck error FS3388: This expression implicitly converts type 'int' to type 'double'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(135,18,135,19): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
+test.fsx(135,18,135,19): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
 
 test.fsx(135,18,135,19): typecheck error FS3388: This expression implicitly converts type 'int' to type 'C'. See https://aka.ms/fsharp-implicit-convs.
 
@@ -141,7 +141,7 @@ test.fsx(140,18,140,19): typecheck error FS3389: This expression uses a built-in
 
 test.fsx(140,18,140,19): typecheck error FS3388: This expression implicitly converts type 'int' to type 'int64'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(145,18,145,19): typecheck error FS3390: This expression uses the implicit conversion 'Decimal.op_Implicit(value: int) : decimal' to convert type 'int' to type 'decimal'.
+test.fsx(145,18,145,19): typecheck error FS3395: This expression uses the implicit conversion 'Decimal.op_Implicit(value: int) : decimal' to convert type 'int' to type 'decimal'.
 
 test.fsx(145,18,145,19): typecheck error FS3388: This expression implicitly converts type 'int' to type 'decimal'. See https://aka.ms/fsharp-implicit-convs.
 
@@ -153,21 +153,21 @@ test.fsx(149,39,149,41): typecheck error FS3391: This expression uses the implic
 
 test.fsx(149,39,149,41): typecheck error FS3388: This expression implicitly converts type 'string' to type 'Xml.Linq.XNamespace'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(154,18,154,20): typecheck error FS3390: This expression uses the implicit conversion 'Xml.Linq.XNamespace.op_Implicit(namespaceName: string) : Xml.Linq.XNamespace' to convert type 'string' to type 'Xml.Linq.XNamespace'.
+test.fsx(154,18,154,20): typecheck error FS3395: This expression uses the implicit conversion 'Xml.Linq.XNamespace.op_Implicit(namespaceName: string) : Xml.Linq.XNamespace' to convert type 'string' to type 'Xml.Linq.XNamespace'.
 
 test.fsx(154,18,154,20): typecheck error FS3388: This expression implicitly converts type 'string' to type 'Xml.Linq.XNamespace'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(159,18,159,21): typecheck error FS3390: This expression uses the implicit conversion 'Xml.Linq.XName.op_Implicit(expandedName: string) : Xml.Linq.XName' to convert type 'string' to type 'Xml.Linq.XName'.
+test.fsx(159,18,159,21): typecheck error FS3395: This expression uses the implicit conversion 'Xml.Linq.XName.op_Implicit(expandedName: string) : Xml.Linq.XName' to convert type 'string' to type 'Xml.Linq.XName'.
 
 test.fsx(159,18,159,21): typecheck error FS3388: This expression implicitly converts type 'string' to type 'Xml.Linq.XName'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(165,18,165,19): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
+test.fsx(165,18,165,19): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
 
 test.fsx(165,18,165,19): typecheck error FS3388: This expression implicitly converts type 'int' to type 'C'. See https://aka.ms/fsharp-implicit-convs.
 
-test.fsx(172,18,172,21): typecheck error FS3390: This expression uses the implicit conversion 'static member Y.op_Implicit: y: Y -> X' to convert type 'Y' to type 'X'.
+test.fsx(172,18,172,21): typecheck error FS3395: This expression uses the implicit conversion 'static member Y.op_Implicit: y: Y -> X' to convert type 'Y' to type 'X'.
 
-test.fsx(172,18,172,21): typecheck error FS3390: This expression uses the implicit conversion 'static member Y.op_Implicit: y: Y -> X' to convert type 'Y' to type 'X'.
+test.fsx(172,18,172,21): typecheck error FS3395: This expression uses the implicit conversion 'static member Y.op_Implicit: y: Y -> X' to convert type 'Y' to type 'X'.
 
 test.fsx(178,20,178,21): typecheck error FS3391: This expression uses the implicit conversion 'static member C.op_Implicit: x: 'T -> C<'T>' to convert type 'int' to type 'C<int>'. See https://aka.ms/fsharp-implicit-convs. This warning may be disabled using '#nowarn "3391".
 
@@ -592,7 +592,7 @@ test.fsx(463,18,463,19): typecheck error FS0001: This expression was expected to
 but here has type
     'int'    
 
-test.fsx(471,18,471,19): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
+test.fsx(471,18,471,19): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: int -> C' to convert type 'int' to type 'C'.
 
 test.fsx(471,18,471,19): typecheck error FS3388: This expression implicitly converts type 'int' to type 'C'. See https://aka.ms/fsharp-implicit-convs.
 
@@ -602,25 +602,25 @@ test.fsx(482,18,482,21): typecheck error FS3387: This expression has type 'B' an
    static member B.op_Implicit: x: B -> C
    static member C.op_Implicit: x: B -> C
 
-test.fsx(482,18,482,21): typecheck error FS3390: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(482,18,482,21): typecheck error FS3395: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
 test.fsx(482,18,482,21): typecheck error FS3387: This expression has type 'B' and is only made compatible with type 'C' through an ambiguous implicit conversion. Consider using an explicit call to 'op_Implicit'. The applicable implicit conversions are:
    static member B.op_Implicit: x: B -> C
    static member C.op_Implicit: x: B -> C
 
-test.fsx(482,18,482,21): typecheck error FS3390: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(482,18,482,21): typecheck error FS3395: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(507,18,507,21): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(507,18,507,21): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(507,18,507,21): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(507,18,507,21): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(519,18,519,21): typecheck error FS3390: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(519,18,519,21): typecheck error FS3395: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(519,18,519,21): typecheck error FS3390: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(519,18,519,21): typecheck error FS3395: This expression uses the implicit conversion 'static member B.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(538,18,538,21): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(538,18,538,21): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
-test.fsx(538,18,538,21): typecheck error FS3390: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
+test.fsx(538,18,538,21): typecheck error FS3395: This expression uses the implicit conversion 'static member C.op_Implicit: x: B -> C' to convert type 'B' to type 'C'.
 
 test.fsx(543,30,543,31): typecheck error FS0001: This expression was expected to have type
     'float32'    
diff --git a/tests/fsharp/tests.fs b/tests/fsharp/tests.fs
index b9f831522bb..b17914427c3 100644
--- a/tests/fsharp/tests.fs
+++ b/tests/fsharp/tests.fs
@@ -110,7 +110,7 @@ module CoreTests =
     [<Test>]
     let ``auto-widen-version-preview-warns-on``() = 
         let cfg = testConfig "core/auto-widen/preview"
-        let cfg = { cfg with fsc_flags = cfg.fsc_flags + " --warnon:3388 --warnon:3389 --warnon:3390 --warnaserror+ --define:NEGATIVE" }
+        let cfg = { cfg with fsc_flags = cfg.fsc_flags + " --warnon:3388 --warnon:3389 --warnon:3395 --warnaserror+ --define:NEGATIVE" }
         singleVersionedNegTest cfg "preview" "test"
 
     [<Test>]