diff --git a/src/axl.h b/src/axl.h
index 7a463c2..b7962f4 100644
--- a/src/axl.h
+++ b/src/axl.h
@@ -8,7 +8,7 @@ extern "C" {
 
 #define AXL_SUCCESS (0)
 
-#define AXL_VERSION "0.3.0"
+#define AXL_VERSION "0.4.0"
 
 /** \defgroup axl AXL
  *  \brief Asynchronous Transfer Library