diff --git a/src/glx/clientinfo.c b/src/glx/clientinfo.c
index ebd4545ad11..14e0e44a832 100644
--- a/src/glx/clientinfo.c
+++ b/src/glx/clientinfo.c
@@ -123,6 +123,10 @@ glxSendClientInfo(struct glx_display *glx_dpy, int screen)
    for (i = 0; i < ScreenCount(glx_dpy->dpy); i++) {
       struct glx_screen *src = glx_dpy->screens[i];
 
+      if (src == NULL) {
+          continue;
+      }
+
       const char *haystack = src->serverGLXexts;
       while (haystack != NULL) {
     char *match = strstr(haystack, "GLX_ARB_create_context");