diff --git a/flake.nix b/flake.nix
index 62ea3cf00..2e9e73934 100644
--- a/flake.nix
+++ b/flake.nix
@@ -465,6 +465,10 @@
 
             src = self;
 
+            configureFlags = [
+              "CXXFLAGS=-I${lib.getDev pkgs.rapidcheck}/extras/gtest/include"
+            ];
+
             enableParallelBuilding = true;
 
             nativeBuildInputs = nativeBuildDeps;