diff --git a/zokrates_cli/examples/book/constant_definition.zok b/zokrates_cli/examples/book/constant_definition.zok
index 016f231c..10b31ec7 100644
--- a/zokrates_cli/examples/book/constant_definition.zok
+++ b/zokrates_cli/examples/book/constant_definition.zok
@@ -1,4 +1,4 @@
-const field BN128_GROUP_MODULUS = 21888242871839275222246405745257275088548364400416034343698204186575808495617
+const field PRIME = 31
 
 def main() -> field:
-    return BN128_GROUP_MODULUS
\ No newline at end of file
+    return PRIME
\ No newline at end of file