diff --git a/contiki-cpc/ctk/ctk-conio-service.c b/contiki-cpc/ctk/ctk-conio-service.c
index 08f52c1..c2ea4c0 100644
--- a/contiki-cpc/ctk/ctk-conio-service.c
+++ b/contiki-cpc/ctk/ctk-conio-service.c
@@ -448,13 +448,11 @@
       }
     }
 
-    if(clipy2 < y1 + h) {
-      if(y1 >= clipy2) {
-	h = 0;
-      } else {
-	h = clipy2 - y1;
-      }
-    }
+	if(y1 >= clipy2) {
+		h = 0;
+	} else if(y1 + h > clipy2) {
+		h = clipy2 - y1;
+	}
 
     cvlinexy(x, y1, h);
     cvlinexy(x2, y1, h);