diff --git a/psycopg/connection.h b/psycopg/connection.h
index c52abc9f..d15c9c64 100644
--- a/psycopg/connection.h
+++ b/psycopg/connection.h
@@ -71,7 +71,7 @@ extern HIDDEN PyTypeObject connectionType;
 
 struct connectionObject_notice {
     struct connectionObject_notice *next;
-    const char *message;
+    char *message;
 };
 
 /* the typedef is forward-declared in psycopg.h */
diff --git a/psycopg/connection_int.c b/psycopg/connection_int.c
index aea2841c..8fce908d 100644
--- a/psycopg/connection_int.c
+++ b/psycopg/connection_int.c
@@ -154,7 +154,7 @@ conn_notice_clean(connectionObject *self)
     while (notice != NULL) {
         tmp = notice;
         notice = notice->next;
-        free((void*)tmp->message);
+        free(tmp->message);
         free(tmp);
     }