diff --git a/tests/include/lib/edid-test.h b/tests/include/lib/edid-test.h
index 073905d..8327748 100644
--- a/tests/include/lib/edid-test.h
+++ b/tests/include/lib/edid-test.h
@@ -43,7 +43,8 @@
 	uint8_t checksum;
 } __packed;
 
-_Static_assert(sizeof(struct edid_raw) == 128);
+_Static_assert(sizeof(struct edid_raw) == 128,
+	       "assert failed: edid_raw size mismatch");
 
 #define EDID_HEADER_RAW		{ 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00 }
 #define EDID_HEADER_INVALID_RAW	{ 0, 0, 0, 0, 0, 0, 0, 0 }