diff --git a/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/all-packages.nix b/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/all-packages.nix
index 95478a87fb32..3fbe2d5e51dc 100644
--- a/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/all-packages.nix
+++ b/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/all-packages.nix
@@ -1,3 +1,4 @@
 self: super: {
   foo = self._internalCallByNamePackageFile ./foo.nix;
+  bar = self._internalCallByNamePackageFile ./foo.nix;
 }
diff --git a/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/pkgs/by-name/fo/foo/package.nix b/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/pkgs/by-name/fo/foo/package.nix
new file mode 100644
index 000000000000..a1b92efbbadb
--- /dev/null
+++ b/pkgs/test/nixpkgs-check-by-name/tests/internalCallPackage/pkgs/by-name/fo/foo/package.nix
@@ -0,0 +1 @@
+{ someDrv }: someDrv
diff --git a/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/all-packages.nix b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/all-packages.nix
new file mode 100644
index 000000000000..3398e974cb6b
--- /dev/null
+++ b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/all-packages.nix
@@ -0,0 +1,3 @@
+self: super: builtins.mapAttrs (name: value: value) {
+  foo = self.someDrv;
+}
diff --git a/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/default.nix b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/default.nix
new file mode 100644
index 000000000000..861260cdca4b
--- /dev/null
+++ b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/default.nix
@@ -0,0 +1 @@
+import <test-nixpkgs> { root = ./.; }
diff --git a/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/expected b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/expected
new file mode 100644
index 000000000000..9df788191ece
--- /dev/null
+++ b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/expected
@@ -0,0 +1 @@
+pkgs.foo: This attribute is manually defined (most likely in pkgs/top-level/all-packages.nix), which is only allowed if the definition is of the form `pkgs.callPackage pkgs/by-name/fo/foo/package.nix { ... }` with a non-empty second argument.
diff --git a/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/pkgs/by-name/fo/foo/package.nix b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/pkgs/by-name/fo/foo/package.nix
new file mode 100644
index 000000000000..a1b92efbbadb
--- /dev/null
+++ b/pkgs/test/nixpkgs-check-by-name/tests/unknown-location/pkgs/by-name/fo/foo/package.nix
@@ -0,0 +1 @@
+{ someDrv }: someDrv