diff --git a/FsCheck Release Notes.md b/FsCheck Release Notes.md
index f9292c6c..0726c60e 100644
--- a/FsCheck Release Notes.md	
+++ b/FsCheck Release Notes.md	
@@ -1,3 +1,6 @@
+### 2.16.4 - To Be Released
+
+
 ### 2.16.3 - 4 September 2021
 
 * Allow configuration in FsCheck.Xunit.PropertiesAttribute to affect properties on nested types or modules. PropertiesAttribute on the closest enclosing type takes precedence.
diff --git a/src/FsCheck.NUnit/AssemblyInfo.fs b/src/FsCheck.NUnit/AssemblyInfo.fs
index 46ecdfe1..be93950a 100644
--- a/src/FsCheck.NUnit/AssemblyInfo.fs
+++ b/src/FsCheck.NUnit/AssemblyInfo.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FsCheck.NUnit")>]
 [<assembly: AssemblyProductAttribute("FsCheck.NUnit")>]
 [<assembly: AssemblyDescriptionAttribute("Integrates FsCheck with NUnit")>]
-[<assembly: AssemblyVersionAttribute("2.16.3")>]
-[<assembly: AssemblyFileVersionAttribute("2.16.3")>]
+[<assembly: AssemblyVersionAttribute("2.16.4")>]
+[<assembly: AssemblyFileVersionAttribute("2.16.4")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FsCheck.NUnit"
     let [<Literal>] AssemblyProduct = "FsCheck.NUnit"
     let [<Literal>] AssemblyDescription = "Integrates FsCheck with NUnit"
-    let [<Literal>] AssemblyVersion = "2.16.3"
-    let [<Literal>] AssemblyFileVersion = "2.16.3"
+    let [<Literal>] AssemblyVersion = "2.16.4"
+    let [<Literal>] AssemblyFileVersion = "2.16.4"
diff --git a/src/FsCheck.Xunit/AssemblyInfo.fs b/src/FsCheck.Xunit/AssemblyInfo.fs
index 7aeac97a..12fbec2b 100644
--- a/src/FsCheck.Xunit/AssemblyInfo.fs
+++ b/src/FsCheck.Xunit/AssemblyInfo.fs
@@ -6,8 +6,8 @@ open System.Runtime.CompilerServices
 [<assembly: AssemblyTitleAttribute("FsCheck.Xunit")>]
 [<assembly: AssemblyProductAttribute("FsCheck.Xunit")>]
 [<assembly: AssemblyDescriptionAttribute("Integrates FsCheck with xUnit.NET")>]
-[<assembly: AssemblyVersionAttribute("2.16.3")>]
-[<assembly: AssemblyFileVersionAttribute("2.16.3")>]
+[<assembly: AssemblyVersionAttribute("2.16.4")>]
+[<assembly: AssemblyFileVersionAttribute("2.16.4")>]
 [<assembly: InternalsVisibleToAttribute("FsCheck.Test")>]
 do ()
 
@@ -15,6 +15,6 @@ module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FsCheck.Xunit"
     let [<Literal>] AssemblyProduct = "FsCheck.Xunit"
     let [<Literal>] AssemblyDescription = "Integrates FsCheck with xUnit.NET"
-    let [<Literal>] AssemblyVersion = "2.16.3"
-    let [<Literal>] AssemblyFileVersion = "2.16.3"
+    let [<Literal>] AssemblyVersion = "2.16.4"
+    let [<Literal>] AssemblyFileVersion = "2.16.4"
     let [<Literal>] InternalsVisibleTo = "FsCheck.Test"
diff --git a/src/FsCheck/AssemblyInfo.fs b/src/FsCheck/AssemblyInfo.fs
index fcf13a48..3b92f741 100644
--- a/src/FsCheck/AssemblyInfo.fs
+++ b/src/FsCheck/AssemblyInfo.fs
@@ -6,8 +6,8 @@ open System.Runtime.CompilerServices
 [<assembly: AssemblyTitleAttribute("FsCheck")>]
 [<assembly: AssemblyProductAttribute("FsCheck")>]
 [<assembly: AssemblyDescriptionAttribute("FsCheck is a tool for testing .NET programs automatically using randomly generated test cases.")>]
-[<assembly: AssemblyVersionAttribute("2.16.3")>]
-[<assembly: AssemblyFileVersionAttribute("2.16.3")>]
+[<assembly: AssemblyVersionAttribute("2.16.4")>]
+[<assembly: AssemblyFileVersionAttribute("2.16.4")>]
 [<assembly: InternalsVisibleToAttribute("FsCheck.Test")>]
 do ()
 
@@ -15,6 +15,6 @@ module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FsCheck"
     let [<Literal>] AssemblyProduct = "FsCheck"
     let [<Literal>] AssemblyDescription = "FsCheck is a tool for testing .NET programs automatically using randomly generated test cases."
-    let [<Literal>] AssemblyVersion = "2.16.3"
-    let [<Literal>] AssemblyFileVersion = "2.16.3"
+    let [<Literal>] AssemblyVersion = "2.16.4"
+    let [<Literal>] AssemblyFileVersion = "2.16.4"
     let [<Literal>] InternalsVisibleTo = "FsCheck.Test"
diff --git a/src/FsCheck/Runner.fs b/src/FsCheck/Runner.fs
index 676898fb..5f04a13e 100644
--- a/src/FsCheck/Runner.fs
+++ b/src/FsCheck/Runner.fs
@@ -246,7 +246,7 @@ module Runner =
                     name data.NumberOfTests (pluralize data.NumberOfTests) (data.Stamps |> stampsToString)
         | TestResult.False (data, originalArgs, args, Outcome.Exception exc, usedSeed) -> 
             onFailureToString name data originalArgs args usedSeed
-            + sprintf "with exception:%s%O%s" newline exc newline
+            + sprintf "with exception:%s%A%s" newline exc newline
         | TestResult.False (data, _, args, Outcome.Timeout i, usedSeed) -> 
             sprintf "%sTimeout of %i milliseconds exceeded, after %i test%s (%i shrink%s) (%A):%s" 
                 name i data.NumberOfTests (pluralize data.NumberOfTests) data.NumberOfShrinks (pluralize data.NumberOfShrinks) usedSeed newline