diff -r fbc33813265b -r 2bf1da3c411e src/logging.c
--- a/src/logging.c	Thu Jun 21 16:00:37 2018 +0200
+++ b/src/logging.c	Thu Jun 21 16:10:19 2018 +0200
@@ -71,12 +71,12 @@
         const unsigned int line, const char *format, ...) {
     if (level <= logger->level) {
         char msg[UCX_LOGGER_MSGMAX];
-        char *text;
+        const char *text;
         size_t k = 0;
         size_t n;
         
         if ((logger->mask & UCX_LOGGER_LEVEL) > 0) {
-            text = (char*) ucx_map_int_get(logger->levels, level);
+            text = (const char*) ucx_map_int_get(logger->levels, level);
             if (!text) {
                 text = "[UNKNOWN]";
             }