diff --git a/src/libraries/Common/src/Interop/OSX/Interop.libobjc.cs b/src/libraries/Common/src/Interop/OSX/Interop.libobjc.cs
index 799bfd19e0d5e..fc93bf18d8b7d 100644
--- a/src/libraries/Common/src/Interop/OSX/Interop.libobjc.cs
+++ b/src/libraries/Common/src/Interop/OSX/Interop.libobjc.cs
@@ -10,12 +10,6 @@ internal static partial class Interop
 {
     internal static partial class libobjc
     {
-#if TARGET_ARM64
-        private const string MessageSendStructReturnEntryPoint = "objc_msgSend";
-#else
-        private const string MessageSendStructReturnEntryPoint = "objc_msgSend_stret";
-#endif
-
         [StructLayout(LayoutKind.Sequential)]
         private struct NSOperatingSystemVersion
         {
@@ -28,8 +22,8 @@ private struct NSOperatingSystemVersion
         private static extern IntPtr objc_getClass(string className);
         [DllImport(Libraries.libobjc)]
         private static extern IntPtr sel_getUid(string selector);
-        [DllImport(Libraries.libobjc)]
-        private static extern IntPtr objc_msgSend(IntPtr basePtr, IntPtr selector);
+        [DllImport(Libraries.libobjc, EntryPoint = "objc_msgSend")]
+        private static extern IntPtr intptr_objc_msgSend(IntPtr basePtr, IntPtr selector);
 
         internal static Version GetOperatingSystemVersion()
         {
@@ -37,12 +31,15 @@ internal static Version GetOperatingSystemVersion()
             int minor = 0;
             int patch = 0;
 
-            IntPtr processInfo = objc_msgSend(objc_getClass("NSProcessInfo"), sel_getUid("processInfo"));
+            IntPtr processInfo = intptr_objc_msgSend(objc_getClass("NSProcessInfo"), sel_getUid("processInfo"));
 
             if (processInfo != IntPtr.Zero)
             {
-                NSOperatingSystemVersion osVersion = get_operatingSystemVersion(processInfo, sel_getUid("operatingSystemVersion"));
-
+#if TARGET_ARM64
+                NSOperatingSystemVersion osVersion = NSOperatingSystemVersion_objc_msgSend(processInfo, sel_getUid("operatingSystemVersion"));
+#else
+                NSOperatingSystemVersion_objc_msgSend_stret(out NSOperatingSystemVersion osVersion, processInfo, sel_getUid("operatingSystemVersion"));
+#endif
                 checked
                 {
                     major = (int)osVersion.majorVersion;
@@ -63,7 +60,10 @@ internal static Version GetOperatingSystemVersion()
             return new Version(major, minor, patch);
         }
 
-        [DllImport(Libraries.libobjc, EntryPoint = MessageSendStructReturnEntryPoint)]
-        private static extern NSOperatingSystemVersion get_operatingSystemVersion(IntPtr basePtr, IntPtr selector);
+        [DllImport(Libraries.libobjc, EntryPoint = "objc_msgSend")]
+        private static extern NSOperatingSystemVersion NSOperatingSystemVersion_objc_msgSend(IntPtr basePtr, IntPtr selector);
+
+        [DllImport(Libraries.libobjc, EntryPoint = "objc_msgSend_stret")]
+        private static extern void NSOperatingSystemVersion_objc_msgSend_stret(out NSOperatingSystemVersion osVersion, IntPtr basePtr, IntPtr selector);
     }
 }
diff --git a/src/libraries/System.Drawing.Common/src/System/Drawing/macFunctions.cs b/src/libraries/System.Drawing.Common/src/System/Drawing/macFunctions.cs
index 16523523fb295..a5d9bfd74b76b 100644
--- a/src/libraries/System.Drawing.Common/src/System/Drawing/macFunctions.cs
+++ b/src/libraries/System.Drawing.Common/src/System/Drawing/macFunctions.cs
@@ -69,13 +69,12 @@ internal static class MacSupport
 
         internal static CocoaContext GetCGContextForNSView(IntPtr handle)
         {
-            IntPtr graphicsContext = objc_msgSend(objc_getClass("NSGraphicsContext"), sel_registerName("currentContext"));
-            IntPtr ctx = objc_msgSend(graphicsContext, sel_registerName("graphicsPort"));
-            Rect bounds = default;
+            IntPtr graphicsContext = intptr_objc_msgSend(objc_getClass("NSGraphicsContext"), sel_registerName("currentContext"));
+            IntPtr ctx = intptr_objc_msgSend(graphicsContext, sel_registerName("graphicsPort"));
 
             CGContextSaveGState(ctx);
 
-            objc_msgSend_stret(ref bounds, handle, sel_registerName("bounds"));
+            Rect_objc_msgSend_stret(out Rect bounds, handle, sel_registerName("bounds"));
 
             var isFlipped = bool_objc_msgSend(handle, sel_registerName("isFlipped"));
             if (isFlipped)
@@ -211,13 +210,12 @@ internal static void ReleaseContext(IntPtr port, IntPtr context)
         #region Cocoa Methods
         [DllImport("libobjc.dylib")]
         public static extern IntPtr objc_getClass(string className);
-        [DllImport("libobjc.dylib")]
-        public static extern IntPtr objc_msgSend(IntPtr basePtr, IntPtr selector, string argument);
-        [DllImport("libobjc.dylib")]
-        public static extern IntPtr objc_msgSend(IntPtr basePtr, IntPtr selector);
-        [DllImport("libobjc.dylib")]
-        public static extern void objc_msgSend_stret(ref Rect arect, IntPtr basePtr, IntPtr selector);
         [DllImport("libobjc.dylib", EntryPoint = "objc_msgSend")]
+        public static extern IntPtr intptr_objc_msgSend(IntPtr basePtr, IntPtr selector);
+        [DllImport("libobjc.dylib", EntryPoint = "objc_msgSend_stret")]
+        public static extern void Rect_objc_msgSend_stret(out Rect arect, IntPtr basePtr, IntPtr selector);
+        [DllImport("libobjc.dylib", EntryPoint = "objc_msgSend")]
+        [return:MarshalAs(UnmanagedType.U1)]
         public static extern bool bool_objc_msgSend(IntPtr handle, IntPtr selector);
         [DllImport("libobjc.dylib")]
         public static extern IntPtr sel_registerName(string selectorName);