diff --git a/Engine/lib/nativeFileDialogs/CMakeLists.txt b/Engine/lib/nativeFileDialogs/CMakeLists.txt
index 1d0454bc6..f40f44dde 100644
--- a/Engine/lib/nativeFileDialogs/CMakeLists.txt
+++ b/Engine/lib/nativeFileDialogs/CMakeLists.txt
@@ -5,7 +5,7 @@ set(TORQUE_NFD_COMMON_SOURCES "${TORQUE_NFD_ROOT}/nfd_common.c")
 set(TORQUE_NFD_INCLUDE_DIRECTORIES "${TORQUE_NFD_ROOT}" "${TORQUE_NFD_ROOT}/include")
 
 if (APPLE)
-  set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_cocoa.m")
+  set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_cocoa.mm")
 elseif (UNIX)
   if (TORQUE_USE_ZENITY)
     set(TORQUE_NFD_SOURCES ${TORQUE_NFD_COMMON_SOURCES} "${TORQUE_NFD_ROOT}/nfd_zenity.c")
diff --git a/Engine/lib/nativeFileDialogs/nfd_cocoa.m b/Engine/lib/nativeFileDialogs/nfd_cocoa.mm
similarity index 100%
rename from Engine/lib/nativeFileDialogs/nfd_cocoa.m
rename to Engine/lib/nativeFileDialogs/nfd_cocoa.mm