diff --git a/src/index.js b/src/index.js
index 63c0f0f..983a592 100644
--- a/src/index.js
+++ b/src/index.js
@@ -102,12 +102,21 @@ function run_scratch_file(filename) {
   }
 
   vm.runtime.on('QUESTION', function (question) {
-    if (question !== null) {
-      if (question === 'read_token') {
-        vm.runtime.emit('ANSWER', Kattio.nextToken());
-      } else {
-        vm.runtime.emit('ANSWER', Kattio.nextLine());
+    try {
+      if (question !== null) {
+        if (question === 'read_token') {
+          vm.runtime.emit('ANSWER', Kattio.nextToken());
+        } else {
+          vm.runtime.emit('ANSWER', Kattio.nextLine());
+        }
       }
+    } catch (e) {
+      writeStderrSync(
+        'scratch-vm encountered an error: Could not read input: ' +
+          e.message +
+          '\n'
+      );
+      process.exit(1);
     }
   });
 
diff --git a/src/kattio.js b/src/kattio.js
index ecd14a1..2db1107 100644
--- a/src/kattio.js
+++ b/src/kattio.js
@@ -32,7 +32,10 @@ const Kattio = {
 
   _readUntil: function (stop) {
     this._ensure();
-    if (this._bufPos === this._bufLen) throw new Error('eof');
+    if (this._bufPos === this._bufLen) {
+      throw new Error('End of file reached');
+    }
+
     var start = this._bufPos;
     var before = null;
     for (;;) {
@@ -51,7 +54,9 @@ const Kattio = {
       if (this._bufPos === this._bufLen || stop(this._buf[this._bufPos])) break;
       this._bufPos++;
     }
-    if (!before) return this._buf.toString('utf8', start, this._bufPos);
+    if (!before) {
+      return this._buf.toString('utf8', start, this._bufPos);
+    }
     var after = this._buf.slice(start, this._bufPos);
     var res = Buffer.alloc(before.length + after.length);
     before.copy(res);