diff --git a/lib/services/block/index.js b/lib/services/block/index.js
index 73ad6be8..ba6a1aac 100644
--- a/lib/services/block/index.js
+++ b/lib/services/block/index.js
@@ -725,12 +725,12 @@ BlockService.prototype._findLatestValidBlockHeader = function(callback) {
         log.error('Block Service: we could not locate any of our recent block hashes in the header service ' + 'index. Perhaps our header service sync\'ed to the wrong chain?');
         }
     // assert(header, 'Block Service: we could not locate any of our recent block hashes in the header service ' + 'index. Perhaps our header service sync\'ed to the wrong chain?');
-
-      if (header.height > self._tip.height) { 
-        log.error('Block Service: we found a common ancestor header whose ' + 'height was greater than our current tip. This should be impossible.');
-       }
+	if (typeof header.height !== 'undefined') {
+      		if (header.height > self._tip.height) { 
+        	log.error('Block Service: we found a common ancestor header whose ' + 'height was greater than our current tip. This should be impossible.');
+       		}
     // assert(header.height <= self._tip.height, 'Block Service: we found a common ancestor header whose ' + 'height was greater than our current tip. This should be impossible.');
-
+	}
     callback(null, header);
 
   });