diff --git a/src/debugger.c b/src/debugger.c
index f627a9a..b158ecd 100644
--- a/src/debugger.c
+++ b/src/debugger.c
@@ -734,7 +734,7 @@
 }
 
     static void
-update_has_expr_breakpoint()
+update_has_expr_breakpoint(void)
 {
     int i;
 
@@ -751,7 +751,7 @@
  * Return TRUE if there is any expression breakpoint.
  */
     int
-debug_has_expr_breakpoint()
+debug_has_expr_breakpoint(void)
 {
     return has_expr_breakpoint;
 }