diff --git a/src/parallel64/ports/portio.c b/src/parallel64/ports/portio.c
index 597eed0..09269f5 100644
--- a/src/parallel64/ports/portio.c
+++ b/src/parallel64/ports/portio.c
@@ -42,7 +42,7 @@ uint8_t readport(uint16_t port) {
 }
 
 void writeport(uint16_t port, uint8_t value) {
-    return writeport_cached(port, value);
+    writeport_cached(port, value);
 }
 #endif