diff --git a/lib/blockchain/chain.js b/lib/blockchain/chain.js
index 5e2cd14e..9c305ff7 100644
--- a/lib/blockchain/chain.js
+++ b/lib/blockchain/chain.js
@@ -982,10 +982,10 @@ class Chain extends AsyncEmitter {
 
         let indexWalk = competitor
 
-        // mark invalid_child from tip of fork to first block of fork
-        while (indexWalk.height !== fork.height + 1) {
-          indexWalk = await this.getPrevious(indexWalk)
+        // mark invalid_child from tip of competitor to first block of fork
+        while (indexWalk.height > fork.height) {
           await this.setInvalid(indexWalk.hash)
+          indexWalk = await this.getPrevious(indexWalk)
         }
 
         // check