diff --git a/lib/wrapper.js b/lib/wrapper.js
index a10ed50..1197247 100644
--- a/lib/wrapper.js
+++ b/lib/wrapper.js
@@ -23,7 +23,7 @@ function u8ToBn(u8) {
   return BigInt('0x' + hex.join(''));
 }
 
-
+let startCalled = 0;
 
 module.exports = () => {
   // let state = 0; // idle
@@ -45,7 +45,10 @@ module.exports = () => {
   };
 
   const start = async() => {
-    await _waitForStart(wasm);
+    if( !startCalled ) {
+      await _waitForStart(wasm);
+      startCalled++;
+    }
     bindCWrap();
     bindCallback();
   }
diff --git a/test/wasm_events.js b/test/wasm_events.js
new file mode 100644
index 0000000..33eeb26
--- /dev/null
+++ b/test/wasm_events.js
@@ -0,0 +1,84 @@
+'use strict';
+
+const expect = require('chai').expect;
+const lib = require('../lib/index.js');
+
+describe('wasm events', () => {
+  let inst;
+  // return a promise, and mocha will wait until it resolves
+  before(() => {
+    const fn = async () => {
+      inst = await lib.wasmparser();
+    };
+    return fn();
+  });
+
+  it('$enddefinitions', done => {
+    
+    inst.on('$enddefinitions', () => {
+      expect(inst.info).to.deep.eq({
+        status: 'simulation',
+        varId: 'u)',
+        wires: {
+          top: {
+            clock: '"}G',
+            fruit: {
+              point: 'u)'
+            },
+            leaf: {
+              counter: '{u'
+            }
+          }
+        },
+        stack: [{
+          top: {
+            clock: '"}G',
+            fruit: {
+              point: 'u)'
+            },
+            leaf: {
+              counter: '{u'
+            }
+          }
+        },
+        {
+          clock: '"}G',
+          fruit: {
+            point: 'u)'
+          },
+          leaf: {
+            counter: '{u'
+          }
+        },
+        {
+          point: 'u)'
+        }]
+      });
+    });
+    expect(inst.write(`
+$version Generated by VerilatedVcd $end
+$date Wed Sep 18 22:59:07 2019
+ $end
+$timescale   1ns $end
+
+  $scope   module   top    $end
+    $var wire  1 "}G clock $end
+    $scope module leaf $end
+      $var wire 64 {u counter [63:0] $end
+    $upscope $end
+    $scope module fruit $end
+      $var wire 4 u) point [3:0] $end
+    $upscope $end
+  $upscope $end
+
+  $enddefinitions $end
+`
+    )).to.eq(true);
+
+    done();
+  });
+
+
+});
+
+/* eslint-env mocha */