diff --git a/development/cmake/src/support/CMakeLists.txt b/development/cmake/src/support/CMakeLists.txt
index 4ff45876c8..8e66b49742 100644
--- a/development/cmake/src/support/CMakeLists.txt
+++ b/development/cmake/src/support/CMakeLists.txt
@@ -10,7 +10,7 @@ file(GLOB support_sources ${TOP_SRC_DIR}/src/support/${LYX_CPP_FILES})
 file(GLOB moc_files ${TOP_SRC_DIR}/src/support/${LYX_MOC_FILES})
 list(REMOVE_ITEM support_sources ${moc_files} .)
 if(APPLE)
-	list(APPEND support_sources ${TOP_SRC_DIR}/src/support/AppleSpeller.m)
+	list(APPEND dont_merge ${TOP_SRC_DIR}/src/support/AppleSpeller.m)
 endif()
 
 file(GLOB support_headers ${TOP_SRC_DIR}/src/support/${LYX_HPP_FILES})
@@ -38,7 +38,7 @@ else()
 endif()
 
 # needed to compile tex2lyx in merged mode
-set(dont_merge ${TOP_SRC_DIR}/src/support/gettext.cpp)
+set(dont_merge ${dont_merge} ${TOP_SRC_DIR}/src/support/gettext.cpp)
 
 lyx_add_msvc_pch(support)