diff --git a/src/keycode.c b/src/keycode.c
index f699f9b..f2fc53b 100644
--- a/src/keycode.c
+++ b/src/keycode.c
@@ -366,7 +366,7 @@ keycode()
 #include <conio.h>
 
 int
-keycode()
+keycode(void)
 {
     int code = -1;
     int key  = getch();
@@ -421,7 +421,7 @@ keycode()
 #endif
 
 void
-test_keycodes()
+test_keycodes(void)
 {
     printf("getkeycode() test; press 'q' for exit\n");
     printf("Press 'q' for exit\n\n");
diff --git a/src/keycode.h b/src/keycode.h
index d9abc4c..38ce044 100644
--- a/src/keycode.h
+++ b/src/keycode.h
@@ -5,10 +5,10 @@ extern "C" {
 #endif
 
 int
-keycode();
+keycode(void);
 
 void
-test_keycodes();
+test_keycodes(void);
 
 // key codes ==========================================