diff --git a/src/emucore/Serializer.cxx b/src/emucore/Serializer.cxx
index a6eace3ae..b57bb5696 100644
--- a/src/emucore/Serializer.cxx
+++ b/src/emucore/Serializer.cxx
@@ -86,7 +86,7 @@ void Serializer::rewind()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt32 Serializer::size() const
+size_t Serializer::size() const
 {
   return myStream->tellp();
 }
diff --git a/src/emucore/Serializer.hxx b/src/emucore/Serializer.hxx
index 6f6ca5ac3..4ab23b47f 100644
--- a/src/emucore/Serializer.hxx
+++ b/src/emucore/Serializer.hxx
@@ -64,7 +64,7 @@ class Serializer
     /**
       Returns the current write pointer location.
     */
-    uInt32 size() const;
+    size_t size() const;
 
     /**
       Reads a byte value (unsigned 8-bit) from the current input stream.
diff --git a/src/macos/stella.xcodeproj/project.pbxproj b/src/macos/stella.xcodeproj/project.pbxproj
index 7a46ed1c7..fcf9a48f7 100644
--- a/src/macos/stella.xcodeproj/project.pbxproj
+++ b/src/macos/stella.xcodeproj/project.pbxproj
@@ -3029,6 +3029,7 @@
 					CHEATCODE_SUPPORT,
 					DEBUGGER_SUPPORT,
 					JOYSTICK_SUPPORT,
+					PNG_SUPPORT,
 					SOUND_SUPPORT,
 					WINDOWED_SUPPORT,
 					BSPF_MACOS,
@@ -3082,6 +3083,7 @@
 					CHEATCODE_SUPPORT,
 					DEBUGGER_SUPPORT,
 					JOYSTICK_SUPPORT,
+					PNG_SUPPORT,
 					SOUND_SUPPORT,
 					WINDOWED_SUPPORT,
 					BSPF_MACOS,