diff --git a/cli/asc.js b/cli/asc.js
index 9b30cac365..f9bd9ff99a 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -529,7 +529,7 @@ exports.main = function main(argv, options, callback) {
     transforms = transforms.map(classOrModule => {
       // Except if it’s a legacy module, just pass it through.
       if (typeof classOrModule !== "function") {
-        return classOrModule; 
+        return classOrModule;
       }
       Object.assign(classOrModule.prototype, {
         program,
@@ -881,12 +881,20 @@ exports.main = function main(argv, options, callback) {
   if (opts.trapMode === "clamp") {
     stats.optimizeCount++;
     stats.optimizeTime += measure(() => {
-      module.runPass("trap-mode-clamp");
+      try {
+        module.runPasses(["trap-mode-clamp"]);
+      } catch (e) {
+        crash("runPasses", e);
+      }
     });
   } else if (opts.trapMode === "js") {
     stats.optimizeCount++;
     stats.optimizeTime += measure(() => {
-      module.runPass("trap-mode-js");
+      try {
+        module.runPasses(["trap-mode-js"]);
+      } catch (e) {
+        crash("runPasses", e);
+      }
     });
   } else if (opts.trapMode !== "allow") {
     module.dispose();
diff --git a/src/module.ts b/src/module.ts
index c19ed459f4..1b3283b866 100644
--- a/src/module.ts
+++ b/src/module.ts
@@ -2191,16 +2191,6 @@ export class Module {
     binaryen._BinaryenModuleSetFeatures(this.ref, featureFlags);
   }
 
-  runPass(pass: string, func: FunctionRef = 0): void {
-    var cStr = allocString(pass);
-    if (func) {
-      binaryen._BinaryenFunctionRunPasses(func, this.ref, cStr, 1);
-    } else {
-      binaryen._BinaryenModuleRunPasses(this.ref, cStr, 1);
-    }
-    binaryen._free(cStr);
-  }
-
   runPasses(passes: string[], func: FunctionRef = 0): void {
     var numNames = passes.length;
     var cStrs = new Array<StringRef>(numNames);