diff --git a/src/FsCheck/ReflectArbitrary.fs b/src/FsCheck/ReflectArbitrary.fs
index 6409f66c..3fb3f28d 100644
--- a/src/FsCheck/ReflectArbitrary.fs
+++ b/src/FsCheck/ReflectArbitrary.fs
@@ -191,7 +191,7 @@ module internal ReflectArbitrary =
         else
             fun _ -> []
 
-    let private reflectShrinkObj getShrink o (t:Type) = 
+    let private reflectShrinkObj (getShrink:Type->obj->seq<obj>) o (t:Type) = 
         //assumes that l contains at least one element. 
         let split3 l =
             let rec split3' front m back =
@@ -311,4 +311,4 @@ module internal ReflectArbitrary =
         else
             Seq.empty
 
-    let reflectShrink getShrink (a:'a) = reflectShrinkObj getShrink a (typeof<'a>) |> Seq.map (unbox<'a>)
\ No newline at end of file
+    let reflectShrink<'T> (getShrink: Type -> obj -> seq<obj>) (a:'T) = reflectShrinkObj getShrink a (typeof<'T>) |> Seq.map (unbox<'T>)
\ No newline at end of file
diff --git a/src/FsCheck/TypeClass.fs b/src/FsCheck/TypeClass.fs
index c6cdf3ae..8e611fea 100644
--- a/src/FsCheck/TypeClass.fs
+++ b/src/FsCheck/TypeClass.fs
@@ -51,11 +51,11 @@ module TypeClass =
                     Array <| arr
             | prim -> Primitive prim
  
-    let private getMethods (t: Type) =
+    let private getMethods (t: Type) : seq<MethodInfo> =
         #if NETSTANDARD1_0
         t.GetRuntimeMethods()
         #else
-        t.GetMethods(BindingFlags.Static ||| BindingFlags.Public ||| BindingFlags.FlattenHierarchy ||| BindingFlags.NonPublic ||| BindingFlags.Instance)
+        upcast t.GetMethods(BindingFlags.Static ||| BindingFlags.Public ||| BindingFlags.FlattenHierarchy ||| BindingFlags.NonPublic ||| BindingFlags.Instance)
         #endif
     
     //returns a dictionary of generic types to methodinfo, a catch all, and array types in a list by rank