diff --git a/mac/mcompile/keymap.cpp b/mac/mcompile/keymap.cpp
index 0a9e520f63..c4ae0d6c3f 100644
--- a/mac/mcompile/keymap.cpp
+++ b/mac/mcompile/keymap.cpp
@@ -303,7 +303,6 @@ KMX_DWORD mac_KMX_get_KeyVal_From_KeyCode_dk(const UCKeyboardLayout* keyboard_la
  *         or else the keyval obtained from Keycode and shiftstate and caps;
  */
 KMX_DWORD mac_KMX_get_KeyValUnderlying_From_KeyCodeUnderlying(const UCKeyboardLayout* keyboard_layout, KMX_DWORD kc_underlying, KMX_DWORD vk_ShiftState, PKMX_WCHAR deadKey) {
-  PKMX_WCHAR dky = NULL;
   UInt32 isdk = 0;
   KMX_DWORD keyV;
   int caps = 0;
@@ -315,7 +314,9 @@ KMX_DWORD mac_KMX_get_KeyValUnderlying_From_KeyCodeUnderlying(const UCKeyboardLa
 
   // if there was a deadkey return 0xFFFF and copy deadkey into dky; else return the keyvalue
   if (isdk != 0) {
-    dky = (PKMX_WCHAR)(std::u16string(1, keyV)).c_str();
+    PKMX_WCHAR dky = NULL;
+    std::u16string keyVS(1, keyV);
+    dky = (PKMX_WCHAR) keyVS.c_str();
     *deadKey = *dky;
     return 0xFFFF;
   }
diff --git a/mac/mcompile/mc_kmxfile.cpp b/mac/mcompile/mc_kmxfile.cpp
index d75f3076de..78aa40615c 100644
--- a/mac/mcompile/mc_kmxfile.cpp
+++ b/mac/mcompile/mc_kmxfile.cpp
@@ -285,6 +285,9 @@ LPKMX_KEYBOARD KMX_CopyKeyboard(PKMX_BYTE bufp, PKMX_BYTE base) {
   kbp->dwFlags = ckbp->dwFlags;
   kbp->dwHotKey = ckbp->dwHotKey;
 
+  kbp->dpBitmapOffset = ckbp->dpBitmapOffset;
+  kbp->dwBitmapSize = ckbp->dwBitmapSize;
+
   kbp->dpStoreArray = (LPKMX_STORE)bufp;
   bufp += sizeof(KMX_STORE) * kbp->cxStoreArray;
 
diff --git a/mac/mcompile/meson.build b/mac/mcompile/meson.build
index 5c46335674..161112a305 100644
--- a/mac/mcompile/meson.build
+++ b/mac/mcompile/meson.build
@@ -3,7 +3,9 @@ project('mcompile', 'c', 'cpp',
         meson_version: '>=1.0')
 
 # see https://github.com/keymanapp/keyman/pull/11334#issuecomment-2290784399
-add_project_arguments('-O0', language : 'cpp')
+add_project_arguments('-O1', language : 'cpp')
+
+// _S2 was  // add_project_arguments('-O0', language : 'cpp')
 
 carbon =         dependency('Carbon')