diff --git a/src/wrap_cl.hpp b/src/wrap_cl.hpp
index 42a8205bd84826dc96a6b1661a5e3ccd25058603..1a4cbd480a38107522ec47a089fb097bef581f99 100644
--- a/src/wrap_cl.hpp
+++ b/src/wrap_cl.hpp
@@ -2330,7 +2330,7 @@ namespace pyopencl
           "'shape' must be given");
 
     void *buf = 0;
-    PYOPENCL_BUFFER_SIZE_T len;
+    PYOPENCL_BUFFER_SIZE_T len = 0;
 
 #ifdef PYOPENCL_USE_NEW_BUFFER_INTERFACE
     std::unique_ptr<py_buffer_wrapper> retained_buf_obj;