diff --git a/tools/asn1_compiler.c b/tools/asn1_compiler.c
index 03fb7e03758..c2ca467e18f 100644
--- a/tools/asn1_compiler.c
+++ b/tools/asn1_compiler.c
@@ -409,7 +409,7 @@ static void tokenise(char *buffer, char *end)
 
 			/* Handle string tokens */
 			if (isalpha(*p)) {
-				const char **dir;
+				const char * const *dir;
 
 				/* Can be a directive, type name or element
 				 * name.  Find the end of the name.
@@ -629,7 +629,7 @@ int main(int argc, char **argv)
 		perror(NULL);
 		exit(1);
 	}
-	p = strchr(grammar_name, '.');
+	p = (char *)strchr(grammar_name, '.');
 	if (p)
 		*p = '\0';