diff --git a/mac/mcompile/mcompile.cpp b/mac/mcompile/mcompile.cpp
index c4c5e59288e..1d4591ead09 100644
--- a/mac/mcompile/mcompile.cpp
+++ b/mac/mcompile/mcompile.cpp
@@ -92,6 +92,9 @@ int main(int argc, char* argv[]) {
 
   if (mac_KMX_DoConvert(kmxfile, bDeadkeyConversion)) {  // I4552F
     KMX_SaveKeyboard(kmxfile, outfile);
+  } else {
+    mac_KMX_LogError(L"Failed to convert keyboard (%d)\n", errno);
+    return 3;
   }
 
   delete kmxfile;