diff --git a/vm.rkt b/vm.rkt
index 1dd27b9..b025297 100644
--- a/vm.rkt
+++ b/vm.rkt
@@ -165,11 +165,13 @@
    (lambda (m)
       (let ([c (get-carry m)]
             [z (get-zero m)])
-         (case cc
-            [(NZ) (if (not z) (set-pc addr m) m)]
-            [(Z) (if z (set-pc addr) m)]
-            [(NC) (if (not c) (set-pc addr) m)]
-            [(C) (if c (set-pc addr) m)]))))
+         (if (case cc
+               [(NZ) (not z)]
+               [(Z)  z]
+               [(NC) (not c)]
+               [(C)  c])
+             (set-pc addr m)
+             m))))
 
 (define (jp-uncond addr)
    (lambda (m)