1 files changed, 1 insertions, 1 deletions
diff --git a/lib/compress.js b/lib/compress.js
index 345d8ad6..83c3e6d0 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -950,7 +950,7 @@ merge(Compressor.prototype, {
         def(AST_BlockStatement, block_aborts);
         def(AST_SwitchBranch, block_aborts);
         def(AST_If, function(){
-            return this.alternative && aborts(this.body) && aborts(this.alternative);
+            return this.alternative && aborts(this.body) && aborts(this.alternative) && this;
         });
     })(function(node, func){
         node.DEFMETHOD("aborts", func);