diff --git a/src/V3Broken.cpp b/src/V3Broken.cpp
index 51612ec29..f5ce7c0c7 100644
--- a/src/V3Broken.cpp
+++ b/src/V3Broken.cpp
@@ -74,7 +74,7 @@ public:
         // Called by operator new on any node - only if VL_LEAK_CHECKS
         if (debug()>=9) cout<<"-nodeNew:  "<<cvtToHex(nodep)<<endl;
         NodeMap::iterator iter = s_nodes.find(nodep);
-        if (iter!=s_nodes.end() || (iter->second & FLAG_ALLOCATED)) {
+        if (iter !=s_nodes.end() && (iter->second & FLAG_ALLOCATED)) {
             nodep->v3fatalSrc("Newing AstNode object that is already allocated");
         }
         if (iter == s_nodes.end()) {
@@ -117,8 +117,18 @@ public:
             iter->second |= or_flags;
         }
     }
+    static bool isAllocated(const AstNode* nodep) {
+        // Some generic node has a pointer to this node.  Is it allocated?
+        // Use this when might not be in tree; otherwise use okIfLinkedTo().
+#ifdef VL_LEAK_CHECKS
+        NodeMap::iterator iter = s_nodes.find(nodep);
+        if (iter == s_nodes.end()) return false;
+        if (!(iter->second & FLAG_ALLOCATED)) return false;
+#endif
+        return true;
+    }
     static bool okIfLinkedTo(const AstNode* nodep) {
-        // Someone has a pointer to this node.  Is it kosher?
+        // Some node in tree has a pointer to this node.  Is it kosher?
         NodeMap::iterator iter = s_nodes.find(nodep);
         if (iter == s_nodes.end()) return false;
 #ifdef VL_LEAK_CHECKS
@@ -155,6 +165,11 @@ public:
                     // Use only AstNode::dump instead of the virtual one, as there
                     // may be varp() and other cross links that are bad.
                     if (v3Global.opt.debugCheck()) {
+                        // When get this message, find what forgot to delete the
+                        // node by running GDB, where for node "<e###>" use:
+                        //    watch AstNode::s_editCntGbl==####
+                        //    run
+                        //    bt
                         std::cerr<<"%Error: LeakedNode"<<(it->first->backp()?"Back: ":": ");
                         AstNode* rawp = const_cast<AstNode*>
                             (static_cast<const AstNode*>(it->first));
@@ -295,3 +310,6 @@ void V3Broken::addNewed(AstNode* nodep) {
 void V3Broken::deleted(AstNode* nodep) {
     BrokenTable::deleted(nodep);
 }
+bool V3Broken::isAllocated(AstNode* nodep) {
+    return BrokenTable::isAllocated(nodep);
+}
diff --git a/src/V3Broken.h b/src/V3Broken.h
index 3d4c8351f..62797126b 100644
--- a/src/V3Broken.h
+++ b/src/V3Broken.h
@@ -34,6 +34,7 @@ public:
     static void brokenAll(AstNetlist* nodep);
     static void addNewed(AstNode* nodep);
     static void deleted(AstNode* nodep);
+    static bool isAllocated(AstNode* nodep);
 };
 
 #endif  // Guard
diff --git a/src/V3Const.cpp b/src/V3Const.cpp
index 5ed24f1e4..e8ddb47c7 100644
--- a/src/V3Const.cpp
+++ b/src/V3Const.cpp
@@ -1540,6 +1540,7 @@ private:
                     fromp->dtypeFrom(VN_CAST(fromp->dtypep()->skipRefp(),
                                              NodeArrayDType)->subDTypep());
                 }
+                nodep->deleteTree(); VL_DANGLING(nodep);
             }
         }
         m_selp = NULL;
diff --git a/src/V3Unroll.cpp b/src/V3Unroll.cpp
index d289af6d6..f394ceed9 100644
--- a/src/V3Unroll.cpp
+++ b/src/V3Unroll.cpp
@@ -189,44 +189,48 @@ private:
 
     bool simulateTree(AstNode *nodep, const V3Number *loopValue,
                       AstNode *dtypep, V3Number &outNum) {
-        AstNode* clone = nodep->cloneTree(true);
-        if (!clone) {
+        AstNode* clonep = nodep->cloneTree(true);
+        if (!clonep) {
             nodep->v3fatalSrc("Failed to clone tree");
             return false;
         }
         if (loopValue) {
             m_varValuep = new AstConst(nodep->fileline(), *loopValue);
             // Iteration requires a back, so put under temporary node
-            AstBegin* tempp = new AstBegin(nodep->fileline(), "[EditWrapper]", clone);
+            AstBegin* tempp = new AstBegin(nodep->fileline(), "[EditWrapper]", clonep);
             m_varModeReplace = true;
             iterateAndNextNull(tempp->stmtsp());
             m_varModeReplace = false;
-            clone = tempp->stmtsp()->unlinkFrBackWithNext();
+            clonep = tempp->stmtsp()->unlinkFrBackWithNext();
             tempp->deleteTree();
             tempp = NULL;
             pushDeletep(m_varValuep); m_varValuep = NULL;
         }
         SimulateVisitor simvis;
-        simvis.mainParamEmulate(clone);
+        simvis.mainParamEmulate(clonep);
         if (!simvis.optimizable()) {
             UINFO(3, "Unable to simulate" << endl);
             if (debug()>=9) nodep->dumpTree(cout, "- _simtree: ");
+            clonep->deleteTree(); VL_DANGLING(clonep);
             return false;
         }
         // Fetch the result
-        V3Number* res = simvis.fetchNumberNull(clone);
+        V3Number* res = simvis.fetchNumberNull(clonep);
         if (!res) {
             UINFO(3, "No number returned from simulation" << endl);
+            clonep->deleteTree(); VL_DANGLING(clonep);
             return false;
         }
         // Patch up datatype
         if (dtypep) {
-            AstConst new_con (clone->fileline(), *res);
+            AstConst new_con (clonep->fileline(), *res);
             new_con.dtypeFrom(dtypep);
             outNum = new_con.num();
+            clonep->deleteTree(); VL_DANGLING(clonep);
             return true;
         }
         outNum = *res;
+        clonep->deleteTree(); VL_DANGLING(clonep);
         return true;
     }