diff --git a/src/hyperloglog.c b/src/hyperloglog.c
index ba3a3ab6..fc21ea00 100644
--- a/src/hyperloglog.c
+++ b/src/hyperloglog.c
@@ -1512,7 +1512,7 @@ void pfdebugCommand(client *c) {
         }
 
         hdr = o->ptr;
-        addReplyMultiBulkLen(c,HLL_REGISTERS);
+        addReplyArrayLen(c,HLL_REGISTERS);
         for (j = 0; j < HLL_REGISTERS; j++) {
             uint8_t val;