diff --git a/src/xkbcomp/xkbscan.l b/src/xkbcomp/xkbscan.l
index 276ee8f..d5d35e0 100644
--- a/src/xkbcomp/xkbscan.l
+++ b/src/xkbcomp/xkbscan.l
@@ -35,6 +35,12 @@
 
 extern int yyparse(struct parser_param *param);
 
+#ifdef FLEX_SCANNER
+/* XXX Fix warnings from reentrant flex scanners, due to missing prototypes. */
+extern int yyget_column(yyscan_t yyscanner);
+extern void yyset_column(int column_no, yyscan_t yyscanner);
+#endif
+
 #define YY_USER_ACTION {                \
         yylloc->first_line = yylineno;  \
         yylloc->last_line = yylineno;   \