diff --git a/src/FSharp.Core/option.fs b/src/FSharp.Core/option.fs
index ba8256580ec..1b29141df64 100644
--- a/src/FSharp.Core/option.fs
+++ b/src/FSharp.Core/option.fs
@@ -148,7 +148,7 @@ module Option =
     [<CompiledName("OfNullable")>]
     let inline ofNullable (value: System.Nullable<'T>) =
         if value.HasValue then
-            Some value.Value
+            Some (value.GetValueOrDefault())
         else
             None
 
@@ -338,7 +338,7 @@ module ValueOption =
     [<CompiledName("OfNullable")>]
     let inline ofNullable (value: System.Nullable<'T>) =
         if value.HasValue then
-            ValueSome value.Value
+            ValueSome (value.GetValueOrDefault())
         else
             ValueNone