diff --git a/js/lib/cli.js b/js/lib/cli.js
index 0d5ed0b22..23b63e198 100755
--- a/js/lib/cli.js
+++ b/js/lib/cli.js
@@ -287,6 +287,11 @@ function processInputSync(filepath) {
     if (filepath === '-') {
         input = process.stdin;
         input.resume();
+
+        if (input.isRaw === false) {
+            throw 'Must pipe input or define at least one file.';
+        }
+
         input.setEncoding('utf8');
 
         input.on('data', function(chunk) {
@@ -415,6 +420,7 @@ function checkType(parsed) {
 function checkFiles(parsed) {
     var argv = parsed.argv;
 
+
     if (!parsed.files) {
         parsed.files = [];
     } else {
@@ -427,7 +433,9 @@ function checkFiles(parsed) {
     if (argv.remain.length) {
         // assume any remaining args are files
         argv.remain.forEach(function(f) {
-            parsed.files.push(path.resolve(f));
+            if (f !== '-') {
+                parsed.files.push(path.resolve(f));
+            }
         });
     }
 
@@ -438,13 +446,9 @@ function checkFiles(parsed) {
         parsed.replace = true;
     }
 
-    if (argv.original.indexOf('-') > -1) {
-        // ensure '-' without '-f' still consumes stdin
-        parsed.files.push('-');
-    }
-
     if (!parsed.files.length) {
-        throw 'Must define at least one file.';
+        // read stdin by default
+        parsed.files.push('-');
     }
     debug('files.length ' + parsed.files.length);
 
diff --git a/js/test/shell-smoke-test.sh b/js/test/shell-smoke-test.sh
index fcf68048f..28d7ece22 100755
--- a/js/test/shell-smoke-test.sh
+++ b/js/test/shell-smoke-test.sh
@@ -12,7 +12,8 @@ test_cli_common()
   echo Script: $CLI_SCRIPT
 
   # should find the minimal help output
-  $CLI_SCRIPT 2>&1 | grep -q "Must define at least one file\." || {
+  $CLI_SCRIPT 2>&1 | grep -q "define at least one file\." || {
+      $CLI_SCRIPT 2>&1
       echo "[$CLI_SCRIPT_NAME] Output should be help message."
       exit 1
   }
@@ -77,6 +78,16 @@ test_cli_js_beautify()
       exit 1
   }
 
+  cat $SCRIPT_DIR/../bin/js-beautify.js | $CLI_SCRIPT | diff $SCRIPT_DIR/../bin/js-beautify.js - || {
+      echo "js-beautify output for $SCRIPT_DIR/../bin/js-beautify.js was expected to be unchanged."
+      exit 1
+  }
+
+  cat $SCRIPT_DIR/../bin/js-beautify.js | $CLI_SCRIPT - | diff $SCRIPT_DIR/../bin/js-beautify.js - || {
+      echo "js-beautify output for $SCRIPT_DIR/../bin/js-beautify.js was expected to be unchanged."
+      exit 1
+  }
+
   rm -rf /tmp/js-beautify-mkdir
   $CLI_SCRIPT -o /tmp/js-beautify-mkdir/js-beautify.js $SCRIPT_DIR/../bin/js-beautify.js && diff $SCRIPT_DIR/../bin/js-beautify.js /tmp/js-beautify-mkdir/js-beautify.js || {
       echo "js-beautify output for $SCRIPT_DIR/../bin/js-beautify.js should have been created in /tmp/js-beautify-mkdir/js-beautify.js."
diff --git a/python/jsbeautifier/__init__.py b/python/jsbeautifier/__init__.py
index afeb51a75..68b3507e3 100644
--- a/python/jsbeautifier/__init__.py
+++ b/python/jsbeautifier/__init__.py
@@ -1895,34 +1895,37 @@ def main():
 
 
     if not file:
-        print("Must define at least one file.", file=sys.stderr)
+        file = '-'
+
+    if file == '-' and sys.stdin.isatty():
+        print("Must pipe input or define at least one file.", file=sys.stderr)
         return usage(sys.stderr)
-    else:
-        try:
-            if outfile == 'stdout' and replace and not file == '-':
-                outfile = file
 
-            pretty = beautify_file(file, js_options)
+    try:
+        if outfile == 'stdout' and replace and not file == '-':
+            outfile = file
+
+        pretty = beautify_file(file, js_options)
 
-            if outfile == 'stdout':
+        if outfile == 'stdout':
+            # python automatically converts newlines in text to "\r\n" when on windows
+            # switch to binary to prevent this
+            if sys.platform == "win32":
+                import msvcrt
+                msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+
+            sys.stdout.write(pretty)
+        else:
+            if isFileDifferent(outfile, pretty):
+                mkdir_p(os.path.dirname(outfile))
                 # python automatically converts newlines in text to "\r\n" when on windows
                 # switch to binary to prevent this
-                if sys.platform == "win32":
-                    import msvcrt
-                    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+                with io.open(outfile, 'wt', newline='') as f:
+                    f.write(pretty)
 
-                sys.stdout.write(pretty)
-            else:
-                if isFileDifferent(outfile, pretty):
-                    mkdir_p(os.path.dirname(outfile))
-                    # python automatically converts newlines in text to "\r\n" when on windows
-                    # switch to binary to prevent this
-                    with io.open(outfile, 'wt', newline='') as f:
-                        f.write(pretty)
-
-        except Exception as ex:
-            print(ex, file=sys.stderr)
-            return 1
+    except Exception as ex:
+        print(ex, file=sys.stderr)
+        return 1
 
     # Success
     return 0
diff --git a/python/jsbeautifier/tests/shell-smoke-test.sh b/python/jsbeautifier/tests/shell-smoke-test.sh
index a14f962b7..6a6efffa0 100755
--- a/python/jsbeautifier/tests/shell-smoke-test.sh
+++ b/python/jsbeautifier/tests/shell-smoke-test.sh
@@ -12,7 +12,8 @@ test_cli_common()
     echo Script: $CLI_SCRIPT
 
     # should find the minimal help output
-    $CLI_SCRIPT 2>&1 | grep -q "Must define at least one file\." || {
+    $CLI_SCRIPT 2>&1 | grep -q "define at least one file\." || {
+        $CLI_SCRIPT 2>&1
         echo "[$CLI_SCRIPT_NAME] Output should be help message."
         exit 1
     }
@@ -71,15 +72,24 @@ test_cli_js_beautify()
         exit 1
     }
 
-    # On windows python automatically converts newlines to windows format
-    # This occurs on both pipes and files.
-    # As a short-term workaround, disabling these two tests on windows.
     $CLI_SCRIPT $SCRIPT_DIR/../../../js/bin/js-beautify.js | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - || {
         $CLI_SCRIPT $SCRIPT_DIR/../../../js/bin/js-beautify.js | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - | cat -t -e
         echo "js-beautify output for $SCRIPT_DIR/../../../js/bin/js-beautify.js was expected to be unchanged."
         exit 1
     }
 
+    cat $SCRIPT_DIR/../../../js/bin/js-beautify.js | $CLI_SCRIPT | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - || {
+        $CLI_SCRIPT $SCRIPT_DIR/../../../js/bin/js-beautify.js | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - | cat -t -e
+        echo "js-beautify output for $SCRIPT_DIR/../../../js/bin/js-beautify.js was expected to be unchanged."
+        exit 1
+    }
+
+    cat $SCRIPT_DIR/../../../js/bin/js-beautify.js | $CLI_SCRIPT - | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - || {
+        $CLI_SCRIPT $SCRIPT_DIR/../../../js/bin/js-beautify.js | diff $SCRIPT_DIR/../../../js/bin/js-beautify.js - | cat -t -e
+        echo "js-beautify output for $SCRIPT_DIR/../../../js/bin/js-beautify.js was expected to be unchanged."
+        exit 1
+    }
+
     rm -rf /tmp/js-beautify-mkdir
     $CLI_SCRIPT -o /tmp/js-beautify-mkdir/js-beautify.js $SCRIPT_DIR/../../../js/bin/js-beautify.js && diff $SCRIPT_DIR/../../../js/bin/js-beautify.js /tmp/js-beautify-mkdir/js-beautify.js || {
     $CLI_SCRIPT -o /tmp/js-beautify-mkdir/js-beautify.js $SCRIPT_DIR/../../../js/bin/js-beautify.js && diff $SCRIPT_DIR/../../../js/bin/js-beautify.js /tmp/js-beautify-mkdir/js-beautify.js | cat -t -e