diff --git a/xcode/build_phases/localization_check.sh b/xcode/build_phases/localization_check.sh
index 6cd5c61..9a4407d 100755
--- a/xcode/build_phases/localization_check.sh
+++ b/xcode/build_phases/localization_check.sh
@@ -1,6 +1,6 @@
 # source: https://github.com/iKenndac/verify-string-files
 
-SOURCES_DIR=${1:-${TARGET_NAME}} # first argument or TARGET_NAME
+readonly SOURCES_DIR=${1:-${PROJECT_DIR}} # first argument or PROJECT_DIR
 
 if [ "${CONFIGURATION}" = "DEBUG" ]; then
 	${SOURCES_DIR}/build-scripts/xcode/build_phases/common/localization_check -master ${SOURCES_DIR}/Resources/Base.lproj/Localizable.strings -warning-level warning