diff --git a/src/common/gres.c b/src/common/gres.c
index 2b2d2eec9c8e42dc3db8613b2775659710298e2d..450b31d5077e73b5c2b9893b5bbcb7fe6777a223 100644
--- a/src/common/gres.c
+++ b/src/common/gres.c
@@ -534,7 +534,7 @@ static char *_get_gres_conf(void)
 		return xstrdup(GRES_CONFIG_FILE);
 
 	/* Replace file name on end of path */
-	i = strlen(val) - strlen("slurm.conf") + strlen("gres.conf") + 1;
+	i = strlen(val) - strlen("slurm.conf") + strlen("gres.conf") + 2;
 	rc = xmalloc(i);
 	strcpy(rc, val);
 	val = strrchr(rc, (int)'/');