diff --git a/runtime/CMakeLists.txt b/runtime/CMakeLists.txt
index 67260cff..bbcf5a5e 100644
--- a/runtime/CMakeLists.txt
+++ b/runtime/CMakeLists.txt
@@ -267,9 +267,9 @@ macro(build_runtime d_flags c_flags ld_flags lib_suffix path_suffix)
     if(EXISTS ${RUNTIME_DIR})
         set(GCCBUILTINS "${PROJECT_BINARY_DIR}/gccbuiltins_x86.di") 
         add_custom_command(
-            OUTPUT ${GCCBUILTINS} 
-            COMMAND ${PROJECT_PARENT_DIR}/bin/gen_gccbuiltins ${GCCBUILTINS} "x86"
-            DEPENDS ${PROJECT_PARENT_DIR}/bin/gen_gccbuiltins 
+            OUTPUT ${GCCBUILTINS}
+            COMMAND ${PROJECT_BINARY_DIR}/../bin/gen_gccbuiltins ${GCCBUILTINS} "x86"
+            DEPENDS ${PROJECT_BINARY_DIR}/../bin/gen_gccbuiltins
         )
         if(BUILD_SINGLE_LIB)
             add_library(${RUNTIME_AIO}${target_suffix}