1 files changed, 5 insertions, 2 deletions
diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 10d065400..7cc671597 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -523,7 +523,10 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
     for (unsigned i = 1; i < body->size(); i++) {
       if (body[i][0] == DEFUN) numFunctions++;
     }
-    optimizingBuilder = make_unique<OptimizingIncrementalModuleBuilder>(&wasm, numFunctions);
+    optimizingBuilder = make_unique<OptimizingIncrementalModuleBuilder>(&wasm, numFunctions, [&](PassRunner& passRunner) {
+      // run autodrop first, before optimizations
+      passRunner.add<AutoDrop>();
+    });
   }
 
   // first pass - do almost everything, but function imports and indirect calls
@@ -786,7 +789,7 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
   };
   PassRunner passRunner(&wasm);
   passRunner.add<FinalizeCalls>(this);
-  passRunner.add<AutoDrop>();
+  passRunner.add<AutoDrop>(); // FinalizeCalls may cause us to require additional drops
   if (optimize) passRunner.add("vacuum"); // autodrop can add some garbage
   passRunner.run();