diff --git a/include/cbm.h b/include/cbm.h
index 4bbd278e3..f35f83828 100644
--- a/include/cbm.h
+++ b/include/cbm.h
@@ -153,7 +153,7 @@ struct cbm_dirent {
 unsigned char get_tv (void);
 /* Return the video mode the machine is using. */
 
-#if !defined(__PLUS4__) && !defined(__C16__) && !defined(__CBM610__) && !defined(__PET__)
+#if !defined(__CBM610__) && !defined(__PET__)
 void waitvsync (void);
 /* wait for the start of the next frame */
 #endif
diff --git a/libsrc/plus4/waitvsync.s b/libsrc/plus4/waitvsync.s
new file mode 100644
index 000000000..84654d996
--- /dev/null
+++ b/libsrc/plus4/waitvsync.s
@@ -0,0 +1,12 @@
+
+        .export         _waitvsync
+
+        .include        "plus4.inc"
+
+_waitvsync:
+@l1:
+        lda     TED_VLINEHI
+        and     #$01
+        ora     TED_VLINELO
+        bne     @l1
+        rts