diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 5c049483de23..fe797e4f66e5 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4323,7 +4323,8 @@ bool drm_detect_monitor_audio(struct edid *edid)
 	if (!edid_ext)
 		goto end;
 
-	has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);
+	has_audio = (edid_ext[0] == CEA_EXT &&
+		    (edid_ext[3] & EDID_BASIC_AUDIO) != 0);
 
 	if (has_audio) {
 		DRM_DEBUG_KMS("Monitor has basic audio support\n");