diff --git a/i3bar/src/child.c b/i3bar/src/child.c
index 4b09daa9..8d5e999e 100644
--- a/i3bar/src/child.c
+++ b/i3bar/src/child.c
@@ -233,7 +233,7 @@ static int stdin_end_map(void *context) {
     /* Ensure we have a full_text set, so that when it is missing (or null),
      * i3bar doesn’t crash and the user gets an annoying message. */
     if (!new_block->full_text)
-        new_block->full_text = i3string_from_utf8("SPEC VIOLATION (null)");
+        new_block->full_text = i3string_from_utf8("SPEC VIOLATION: full_text is NULL!");
     if (new_block->urgent)
         ctx->has_urgent = true;
     TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);