diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 8d49eff91a..2051103226 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -4,7 +4,7 @@ test_description='git send-email'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-TEST_PASSES_SANITIZE_LEAK=true
+# no longer TEST_PASSES_SANITIZE_LEAK=true - format-patch --thread leaks
 . ./test-lib.sh
 
 # May be altered later in the test