diff --git a/capnp/helpers/checkCompiler.h b/capnp/helpers/checkCompiler.h
index 7250885..d494b8a 100644
--- a/capnp/helpers/checkCompiler.h
+++ b/capnp/helpers/checkCompiler.h
@@ -8,4 +8,4 @@
 
 #include "capnp/dynamic.h"
 
-static_assert(CAPNP_VERSION >= 3000, "Version of Cap'n Proto C++ Library is too old. Please upgrade to a version >= 0.3 and then re-install this python library");
+static_assert(CAPNP_VERSION >= 4000, "Version of Cap'n Proto C++ Library is too old. Please upgrade to a version >= 0.4 and then re-install this python library");