diff --git a/gtk.c b/gtk.c
index eb686c8..eab6980 100644
--- a/gtk.c
+++ b/gtk.c
@@ -88,7 +88,7 @@
 #ifdef DEBUGGING
 static FILE *debug_fp = NULL;
 
-void dputs(const char *buf)
+static void dputs(const char *buf)
 {
     if (!debug_fp) {
         debug_fp = fopen("debug.log", "w");
diff --git a/windows.c b/windows.c
index e4942f4..7287478 100644
--- a/windows.c
+++ b/windows.c
@@ -73,7 +73,7 @@ static FILE *debug_fp = NULL;
 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
 static int debug_got_console = 0;
 
-void dputs(char *buf)
+static void dputs(char *buf)
 {
     /*DWORD dw;