diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 1d0bb9d0173af5908b46285dbd574642fb20a22e..a816fbcb7618bb8cdbf1f74a4fd2295923c02ea3 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -42,7 +42,7 @@ else
 fi
 
 TEST_NO_CREATE_REPO=t
-TEST_NO_MALLOC_=t
+TEST_NO_MALLOC_CHECK=t
 
 . ../test-lib.sh
 
diff --git a/t/test-lib.sh b/t/test-lib.sh
index aad46066adf0021b721bb3a2e235e2b012f13422..9ecbc409a2d42bb047721bdc72574752ba5c31f3 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -96,7 +96,7 @@ export EDITOR
 # Add libc MALLOC and MALLOC_PERTURB test
 # only if we are not executing the test with valgrind
 if expr " $GIT_TEST_OPTS " : ".* --valgrind " >/dev/null ||
-   test -n "TEST_NO_MALLOC_"
+   test -n "$TEST_NO_MALLOC_CHECK"
 then
 	setup_malloc_check () {
 		: nothing