diff --git a/flang/tools/f18/CMakeLists.txt b/flang/tools/f18/CMakeLists.txt
index 25f633e32546c..fc84bbf09c59d 100644
--- a/flang/tools/f18/CMakeLists.txt
+++ b/flang/tools/f18/CMakeLists.txt
@@ -47,8 +47,8 @@ foreach(filename ${MODULES})
   endif()
   add_custom_command(OUTPUT ${base}.mod
     COMMAND ${CMAKE_COMMAND} -E make_directory ${FLANG_INTRINSIC_MODULES_DIR}
-    COMMAND f18 -fsyntax-only ${FLANG_SOURCE_DIR}/module/${filename}.f90
-    WORKING_DIRECTORY ${FLANG_INTRINSIC_MODULES_DIR}
+    COMMAND f18 -fsyntax-only -module-dir ${FLANG_INTRINSIC_MODULES_DIR}
+      ${FLANG_SOURCE_DIR}/module/${filename}.f90
     DEPENDS f18 ${FLANG_SOURCE_DIR}/module/${filename}.f90 ${depends}
   )
   add_custom_command(OUTPUT ${base}.f18.mod