diff --git a/CHANGELOG b/CHANGELOG
index 35c8fa187..7f5b3614c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+* 1.37.1 (2019-XX-XX)
+
+ * n/a
+
 * 1.37.0 (2019-01-14)
 
  * fixed ArrayObject access with a null value
diff --git a/ext/twig/php_twig.h b/ext/twig/php_twig.h
index 747d75e35..7a9c5861e 100644
--- a/ext/twig/php_twig.h
+++ b/ext/twig/php_twig.h
@@ -15,7 +15,7 @@
 #ifndef PHP_TWIG_H
 #define PHP_TWIG_H
 
-#define PHP_TWIG_VERSION "1.37.0"
+#define PHP_TWIG_VERSION "1.37.1-DEV"
 
 #include "php.h"
 
diff --git a/lib/Twig/Environment.php b/lib/Twig/Environment.php
index 557f2765a..d68149b06 100644
--- a/lib/Twig/Environment.php
+++ b/lib/Twig/Environment.php
@@ -16,12 +16,12 @@
  */
 class Twig_Environment
 {
-    const VERSION = '1.37.0';
-    const VERSION_ID = 13700;
+    const VERSION = '1.37.1-DEV';
+    const VERSION_ID = 13701;
     const MAJOR_VERSION = 1;
     const MINOR_VERSION = 37;
-    const RELEASE_VERSION = 0;
-    const EXTRA_VERSION = '';
+    const RELEASE_VERSION = 1;
+    const EXTRA_VERSION = 'DEV';
 
     protected $charset;
     protected $loader;