diff --git a/include/ep2/dialect/Passes.h b/include/ep2/dialect/Passes.h
index 0e8faec..051d9b1 100644
--- a/include/ep2/dialect/Passes.h
+++ b/include/ep2/dialect/Passes.h
@@ -68,7 +68,7 @@ struct HandlerDependencyAnalysis {
     friend bool operator<(const HandlerFullName &l, const HandlerFullName &r) {
       return std::tie(l.event, l.atom) < std::tie(r.event, r.atom);
     }
-    std::string mangle() const { 
+    std::string mangle() const {
       auto surffix = atom == "" ? "" : "_" + atom;
       return ("__handler_" + event + surffix).str();
     }
@@ -77,7 +77,9 @@ struct HandlerDependencyAnalysis {
       return (event + surffix).str();
     }
 
-    HandlerFullName(std::string event, std::string atom = "") : event(event), atom(atom) {}
+    // NOTE: This constructor stores StringRefs that point into the provided
+    // StringRefs. Callers must ensure the underlying data outlives this object.
+    HandlerFullName(llvm::StringRef event, llvm::StringRef atom = "") : event(event), atom(atom) {}
     HandlerFullName(FuncOp funcOp);
     HandlerFullName(ReturnOp returnOp);
     HandlerFullName(InitOp initOp);
diff --git a/lib/ep2/HandlerReplicationPass.cpp b/lib/ep2/HandlerReplicationPass.cpp
index 798c89d..dc6339e 100644
--- a/lib/ep2/HandlerReplicationPass.cpp
+++ b/lib/ep2/HandlerReplicationPass.cpp
@@ -68,10 +68,10 @@ void HandlerReplicationPass::runOnOperation() {
   is replicated onto island 1, compute units 1,2 then location on
   handler 1 = i1cu1, handler 2 has i1cu2.
   */
+  std::vector<ep2::FuncOp> toErase;
   module->walk([&](ep2::FuncOp funcOp) {
     if (funcOp->getAttr("type").cast<StringAttr>().getValue() == "handler" && !funcOp.isExtern()) {
       parentBlock = funcOp->getBlock();
-      llvm::errs() << funcOp.getSymName().str() << '\n';
       auto instances = cast<mlir::ArrayAttr>(funcOp->getAttr("instances")).getValue();
       int sz = instances.size();
       mlir::Operation::CloneOptions options(true, true);
@@ -80,13 +80,16 @@ void HandlerReplicationPass::runOnOperation() {
       for (int i = 1; i<=sz; ++i) {
         mlir::Operation* cloneOp = funcOp->clone(options);
         cloneOp->setAttr("location", instances[i-1]);
-        
+
         cast<ep2::FuncOp>(cloneOp).setSymName(name + "_" + std::to_string(i));
         toInsert.push_back(cloneOp);
       }
-      funcOp->erase();
+      toErase.push_back(funcOp);
     }
   });
+  for (auto funcOp : toErase) {
+    funcOp->erase();
+  }
   for (mlir::Operation* op : toInsert) {
     parentBlock->push_back(op);
   }
diff --git a/lib/ep2/Passes/GlobalToPartitionPass.cpp b/lib/ep2/Passes/GlobalToPartitionPass.cpp
index 80103c2..3e68444 100644
--- a/lib/ep2/Passes/GlobalToPartitionPass.cpp
+++ b/lib/ep2/Passes/GlobalToPartitionPass.cpp
@@ -40,6 +40,7 @@ class GlobalImportPattern : public OpRewritePattern<GlobalImportOp> {
     assert(global != nullptr);
 
     rewriter.replaceOpWithNewOp<InitOp>(refOp, global.getType());
+    return success();
   }
 };
 } // rewrite pattern
@@ -55,6 +56,7 @@ void GlobalToPartitionPass::runOnOperation() {
     return signalPassFailure();
 
   // remove global op if possible if necessary
+  llvm::SmallVector<GlobalOp> toErase;
   for (auto global : moduleOp.getOps<GlobalOp>()) {
     bool hasUse = false;
     moduleOp->walk([&](GlobalImportOp refOp) {
@@ -63,7 +65,10 @@ void GlobalToPartitionPass::runOnOperation() {
     });
 
     if (!hasUse)
-      global.erase();
+      toErase.push_back(global);
+  }
+  for (auto global : toErase) {
+    global.erase();
   }
 }