diff --git a/libsrc/c65/cputc.s b/libsrc/c65/cputc.s
index 99a81b67d..d9f63c1dd 100644
--- a/libsrc/c65/cputc.s
+++ b/libsrc/c65/cputc.s
@@ -9,6 +9,7 @@
         .export         newline, plot
         .import         gotoxy
         .import         PLOT
+        .importzp       ptr4
 
         .include        "c65.inc"