diff --git a/flake.nix b/flake.nix
index a987bc349..8a7640315 100644
--- a/flake.nix
+++ b/flake.nix
@@ -503,6 +503,12 @@
 
                     #TODO Explicitly requiring tasty-discover shouldn't be necessary - see the commented-out `build-tool-depends` in primer.cabal.
                     tasty-discover = "latest";
+
+                    # Required until http-client-tls mess is resolved.
+                    #
+                    # Ref:
+                    # https://github.com/input-output-hk/haskell.nix/issues/2277
+                    hoogle.index-state = "2024-10-01T00:00:00Z";
                   };
 
                   buildInputs = (with final; [
diff --git a/primer-service/primer-service.cabal b/primer-service/primer-service.cabal
index dfc1c939c..2efe2bac4 100644
--- a/primer-service/primer-service.cabal
+++ b/primer-service/primer-service.cabal
@@ -135,7 +135,7 @@ executable primer-client
     , bytestring            >=0.10.8.2 && <0.13
     , directory
     , exceptions
-    , http-client-tls       ^>=0.3.6.1
+    , http-client-tls       ==0.3.6.3
     , optparse-applicative
     , primer
     , primer-service