diff --git a/management/univention-directory-listener/src/cache.c b/management/univention-directory-listener/src/cache.c
index 2edd8df733..96561275c2 100644
--- a/management/univention-directory-listener/src/cache.c
+++ b/management/univention-directory-listener/src/cache.c
@@ -173,6 +173,11 @@ static size_t determine_mapsize_from_ucr() {
 
 		if ((errno == ERANGE && (mapsize == LONG_MAX || mapsize == LONG_MIN)) || (errno != 0 && mapsize == 0)) {
 			univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_ERROR, "cache_init: Error parsing value of UCR variable %s as number: %s", ucr_var_mapsize, strerror(errno));
+#if __SIZEOF_POINTER__ != 8
+			if (errno == ERANGE && mapsize == LONG_MAX) {
+				univention_debug(UV_DEBUG_LISTENER, UV_DEBUG_ERROR, "cache_init: This is looks like a 32 bit system, where the maximum limit is %d, sorry.", LONG_MAX);
+			}
+#endif
 			exit(EXIT_FAILURE);
 		}
 		if (endptr == mapsize_str) {