diff --git a/src/common/compat.c b/src/common/compat.c
index f03e0a494..73f95d3e3 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -945,6 +945,7 @@ log_credential_status(void)
       strgid = tor_malloc(11);
       if (tor_snprintf(strgid, 11, "%u", (unsigned)sup_gids[i]) == -1) {
         log_warn(LD_GENERAL, "Error printing supplementary GIDs");
+        tor_free(strgid);
         formatting_error = 1;
         goto error;
       }