diff --git a/c64/kernal/ioinit.s b/c64/kernal/ioinit.s
index 2ac59c78..bbde4691 100644
--- a/c64/kernal/ioinit.s
+++ b/c64/kernal/ioinit.s
@@ -1,2 +1,3 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
 ioinit:
+	rts
diff --git a/c64/kernal/ramtas.s b/c64/kernal/ramtas.s
index ef0c76b4..645f68b2 100644
--- a/c64/kernal/ramtas.s
+++ b/c64/kernal/ramtas.s
@@ -1,2 +1,3 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
 ramtas:
+	rts
diff --git a/c64/kernal/restor.s b/c64/kernal/restor.s
index de376639..0844288b 100644
--- a/c64/kernal/restor.s
+++ b/c64/kernal/restor.s
@@ -1,2 +1,3 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
 restor:
+	rts