diff --git a/tests/unit/unittest/gmock_dependency.pri b/tests/unit/unittest/gmock_dependency.pri
index e70edb9e356..a771dc39b74 100644
--- a/tests/unit/unittest/gmock_dependency.pri
+++ b/tests/unit/unittest/gmock_dependency.pri
@@ -1,4 +1,4 @@
-GOOGLETEST_DIR = $$(GOOGLETEST_DIR)
+isEmpty(GOOGLETEST_DIR):GOOGLETEST_DIR=$$(GOOGLETEST_DIR)
 
 isEmpty(GOOGLETEST_DIR):linux-* {
     GTEST_SRC_DIR = /usr/include/gmock