diff --git a/src/dalist_debug.c b/src/dalist_debug.c
index 4461286..92cc5b1 100644
--- a/src/dalist_debug.c
+++ b/src/dalist_debug.c
@@ -91,8 +91,12 @@ static int dalist_dbg_write_posix(
 
 	bytes_written = pfn_write(fildes,buf,nbyte);
 
-	if (bytes_written == nbyte)
+	if (bytes_written < 0)
+		return DALIST_EDEBUGENV;
+
+	else if (bytes_written == (ssize_t)nbyte)
 		return DALIST_OK;
+
 	else
 		return DALIST_EDEBUGENV;
 }