diff --git a/History.md b/History.md
index d71ac0f..0c27dd5 100644
--- a/History.md
+++ b/History.md
@@ -1,15 +1,16 @@
-1.9.2
+1.9.2 / 2013-06-12
 ==================
 
   * refactor; move `streamToBuffer` to a separate module
+  * fixed; .stream(format) without a callback
 
-1.9.1 / 2012-05-07
+1.9.1 / 2013-05-07
 ==================
 
   * fixed; gm().resize(width) always only resizes width
   * fixed; gm('img.gif').format() returns the format of the first frame
 
-1.9.0 / 2012-04-21
+1.9.0 / 2013-04-21
 ==================
 
   * added; node v0.10 support
diff --git a/lib/command.js b/lib/command.js
index a2ca64a..0c15225 100644
--- a/lib/command.js
+++ b/lib/command.js
@@ -86,7 +86,10 @@ module.exports = function (proto) {
    */
 
   proto.stream = function stream (format, callback) {
-    if (!callback) callback = format, format = null;
+    if (!callback && typeof format === 'function') {
+      callback = format;
+      format = null;
+    }
 
     var throughStream;
 
diff --git a/test/streamOutFormat.js b/test/streamOutFormat.js
index f2200f5..4924d26 100644
--- a/test/streamOutFormat.js
+++ b/test/streamOutFormat.js
@@ -19,7 +19,11 @@ module.exports = function (gm, dir, finish, GM) {
   withCallback(function (err) {
     if (err) return finish(err);
 
-    withoutCallback(finish);
+    withoutCallback(function (err) {
+      if (err) return finish(err);
+
+      checkOutputFormat(finish);
+    });
   });
 
   function withCallback(done) {
@@ -38,4 +42,16 @@ module.exports = function (gm, dir, finish, GM) {
     stream.pipe(fs.createWriteStream(dir + '/streamOut2.png'))
     stream.on('end', done)
   }
+
+  function checkOutputFormat(done) {
+    var stream = gm.stream('PNG')
+    stream.on('error', done)
+    GM(stream).format(function (err, value) {
+      if (err)
+        return done(err)
+
+      assert.equal(value.toLowerCase(), 'png')
+      done()
+    })
+  }
 }