diff --git a/xpra/x11/bindings/ximage.pyx b/xpra/x11/bindings/ximage.pyx
index f89cdb10d3..a82f2092b7 100644
--- a/xpra/x11/bindings/ximage.pyx
+++ b/xpra/x11/bindings/ximage.pyx
@@ -61,6 +61,7 @@ cdef extern from "Python.h":
     void PyBuffer_Release(Py_buffer *view)
     int PyBUF_ANY_CONTIGUOUS
     int PyBUF_READ
+    int PyBUF_WRITE
 
 cdef extern from "stdlib.h":
     int posix_memalign(void **memptr, size_t alignment, size_t size)
@@ -315,6 +316,9 @@ cdef class XImageWrapper:
         cdef void *pix_ptr = self.get_pixels_ptr()
         if pix_ptr==NULL:
             return None
+        cdef int flags = PyBUF_READ
+        if self.pixels!=NULL:
+            flags = PyBUF_WRITE
         return PyMemoryView_FromMemory(<char *> pix_ptr, self.get_size(), PyBUF_READ)
 
     def get_sub_image(self, unsigned int x, unsigned int y, unsigned int w, unsigned int h):