diff --git a/flake.nix b/flake.nix
index 70311cc62c6e854d6354060b08c099499d566024..93ce0cbbd8e7c74f6a424594d2b29409ba82993f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -76,6 +76,10 @@
       url = "github:TeofilC/servant?ref=ghc-9.4";
       flake = false;
     };
+    sydtest = {
+      url = "github:NorfairKing/sydtest";
+      flake = false;
+    };
     tasty = {
       url = "github:UnkindPartition/tasty";
       flake = false;
diff --git a/overlay.nix b/overlay.nix
index 76a7a341e3f5b8bd4fb455164e230fcb5b490750..5e4bb1348f94b066c24f27cb5e5a286269e5c20b 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -367,6 +367,10 @@ final: prev: with pkgs.haskell.lib; {
 
   syb = dontCheck (prev.callHackage "syb" "0.7.2.1" { });
 
+  sydtest = dontCheck (prev.callCabal2nix "sydtest" (inputs.sydtest + /sydtest) { });
+
+  sydtest-discover = prev.callCabal2nix "sydtest-discover" (inputs.sydtest + /sydtest-discover) { };
+
   tasty = doJailbreak (prev.callCabal2nix "tasty" (inputs.tasty + /core) { });
 
   tasty-discover = doJailbreak (prev.callHackage "tasty-discover" "5.0.0" { });