diff --git a/cc/androidmk.go b/cc/androidmk.go
index 7f18155..70e1f47 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -134,7 +134,7 @@
 func (test *testBinaryLinker) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
 	test.binaryLinker.AndroidMk(ctx, ret)
 	if Bool(test.testLinker.Properties.Test_per_src) {
-		ret.SubName = test.binaryLinker.Properties.Stem
+		ret.SubName = "_" + test.binaryLinker.Properties.Stem
 	}
 }