diff --git a/backend/postal.c b/backend/postal.c
--- a/backend/postal.c
+++ b/backend/postal.c
@@ -363,7 +363,7 @@
 	/* Handles Dutch Post TNT KIX symbols */
 	/* The same as RM4SCC but without check digit */
 	/* Specification at http://www.tntpost.nl/zakelijk/klantenservice/downloads/kIX_code/download.aspx */
-	char height_pattern[50], localstr[20];
+	char height_pattern[256], localstr[20];
 	unsigned int loopey;
 	int writer, i, h;
 	int error_number; /* zeroes; */