diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
index 04f38181e56a956f2830b4ae12340d921f5cc844..07cd7f65c96500ca341cb5694d174ee57df469ed 100644
--- a/src/util/vircgroup.c
+++ b/src/util/vircgroup.c
@@ -231,16 +231,18 @@ virCgroupPartitionNeedsEscaping(const char *path)
 static int
 virCgroupPartitionEscape(char **path)
 {
-    size_t len = strlen(*path) + 1;
     int rc;
-    char escape = '_';
+    char *newstr = NULL;
 
     if ((rc = virCgroupPartitionNeedsEscaping(*path)) <= 0)
         return rc;
 
-    if (VIR_INSERT_ELEMENT(*path, 0, len, escape) < 0)
+    if (virAsprintf(&newstr, "_%s", *path) < 0)
         return -1;
 
+    VIR_FREE(*path);
+    *path = newstr;
+
     return 0;
 }