diff --git a/src/hotspot/share/opto/cfgnode.cpp b/src/hotspot/share/opto/cfgnode.cpp
index 64ebc562a9e..a5bbf2e052e 100644
--- a/src/hotspot/share/opto/cfgnode.cpp
+++ b/src/hotspot/share/opto/cfgnode.cpp
@@ -2610,6 +2610,10 @@ Node *PhiNode::Ideal(PhaseGVN *phase, bool can_reshape) {
     for( uint i=1; i<req(); ++i ) {// For all paths in
       Node *ii = in(i);
       Node *new_in = MemNode::optimize_memory_chain(ii, at, nullptr, phase);
+      // MemNode::optimize_memory_chain above may kill us!
+      if (outcnt() == 0) {
+        return top;
+      }
       if (ii != new_in ) {
         set_req_X(i, new_in, phase);
         progress = this;