diff --git a/src/Composer/Autoload/ClassMapGenerator.php b/src/Composer/Autoload/ClassMapGenerator.php
index e7547cb04..f98543f88 100644
--- a/src/Composer/Autoload/ClassMapGenerator.php
+++ b/src/Composer/Autoload/ClassMapGenerator.php
@@ -124,7 +124,10 @@ class ClassMapGenerator
         $contents = preg_replace('{"[^"\\\\]*(\\\\.[^"\\\\]*)*"|\'[^\'\\\\]*(\\\\.[^\'\\\\]*)*\'}s', 'null', $contents);
         // strip leading non-php code if needed
         if (substr($contents, 0, 2) !== '<?') {
-            $contents = preg_replace('{^.+?<\?}s', '<?', $contents);
+            $contents = preg_replace('{^.+?<\?}s', '<?', $contents, 1, $replacements);
+            if ($replacements === 0) {
+                return array();
+            }
         }
         // strip non-php blocks in the file
         $contents = preg_replace('{\?>.+<\?}s', '?><?', $contents);
diff --git a/tests/Composer/Test/Autoload/Fixtures/template/notphp.inc b/tests/Composer/Test/Autoload/Fixtures/template/notphp.inc
new file mode 100644
index 000000000..2f1f8733a
--- /dev/null
+++ b/tests/Composer/Test/Autoload/Fixtures/template/notphp.inc
@@ -0,0 +1,11 @@
+/**
+ * AJAX interface for remembering user preferences set on the fly
+ *
+ * Match /preferences/ajax/
+ */
+'preferences_ajax' => array
+(
+    'handler' => array ('midgard_admin_asgard_handler_preferences', 'ajax'),
+    'fixed_args' => array('preferences', 'ajax'),
+    'variable_args' => 0,
+),