diff --git a/src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m b/src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m
index 122200a294bd79dc4bfa70be5f61cf1277f8f88e..58abb492ceaef3bdf8338d47c6e5a65f96cf2490 100644
--- a/src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m
+++ b/src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m
@@ -178,7 +178,7 @@ static grpc_end2end_test_config configs[] = {
 
 
 
-char *roots_filename;
+static char *roots_filename;
 
 @interface CoreCronetEnd2EndTests : XCTestCase