diff --git a/glamor/glamor_egl.c b/glamor/glamor_egl.c
index 31b1faffa..d3c678d6b 100644
--- a/glamor/glamor_egl.c
+++ b/glamor/glamor_egl.c
@@ -989,6 +989,11 @@ glamor_egl_init(ScrnInfoPtr scrn, int fd)
     }
 
     renderer = glGetString(GL_RENDERER);
+    if (!renderer) {
+        xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+                   "glGetString() returned NULL, your GL is broken\n");
+        goto error;
+    }
     if (strstr((const char *)renderer, "llvmpipe")) {
         xf86DrvMsg(scrn->scrnIndex, X_INFO,
                    "Refusing to try glamor on llvmpipe\n");
diff --git a/hw/xwayland/xwayland-glamor-gbm.c b/hw/xwayland/xwayland-glamor-gbm.c
index 25a354bf7..6aa1e4641 100644
--- a/hw/xwayland/xwayland-glamor-gbm.c
+++ b/hw/xwayland/xwayland-glamor-gbm.c
@@ -797,6 +797,7 @@ xwl_glamor_gbm_init_egl(struct xwl_screen *xwl_screen)
         GLAMOR_GL_CORE_VER_MINOR,
         EGL_NONE
     };
+    const GLubyte *renderer;
 
     if (!xwl_gbm->fd_render_node && !xwl_gbm->drm_authenticated) {
         ErrorF("Failed to get wl_drm, disabling Glamor and DRI3\n");
@@ -843,7 +844,12 @@ xwl_glamor_gbm_init_egl(struct xwl_screen *xwl_screen)
         goto error;
     }
 
-    if (strstr((const char *)glGetString(GL_RENDERER), "llvmpipe")) {
+    renderer = glGetString(GL_RENDERER);
+    if (!renderer) {
+        ErrorF("glGetString() returned NULL, your GL is broken\n");
+        goto error;
+    }
+    if (strstr((const char *)renderer, "llvmpipe")) {
         ErrorF("Refusing to try glamor on llvmpipe\n");
         goto error;
     }