diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 1524f9fce..30d7b08ad 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -56,7 +56,7 @@ jobs:
 
       - name: Run doctests
         if: always()
-        run: nix-shell --run postgrest-test-doctests
+        run: postgrest-test-doctests
 
       - name: Check the spec tests for idempotence
         if: always()
diff --git a/nix/tools/tests.nix b/nix/tools/tests.nix
index 940130890..4606b1670 100644
--- a/nix/tools/tests.nix
+++ b/nix/tools/tests.nix
@@ -41,6 +41,8 @@ let
         withEnv = postgrest.env;
       }
       ''
+        # This makes nix-env -iA tests.doctests.bin work.
+        export NIX_GHC=${postgrest.env.NIX_GHC}
         ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:doctests
       '';