diff --git a/subprojects/bahaghari/tests/lib/default.nix b/subprojects/bahaghari/tests/lib/default.nix
index 7283d4d8..54c06c4c 100644
--- a/subprojects/bahaghari/tests/lib/default.nix
+++ b/subprojects/bahaghari/tests/lib/default.nix
@@ -4,6 +4,7 @@ let
   lib = import ../../lib { inherit pkgs; };
 in
 {
+  hex = import ./hex.nix { inherit pkgs lib; };
   trivial = import ./trivial { inherit pkgs lib; };
   tinted-theming = import ./tinted-theming { inherit pkgs lib; };
 }
diff --git a/subprojects/bahaghari/tests/lib/hex.nix b/subprojects/bahaghari/tests/lib/hex.nix
new file mode 100644
index 00000000..fe8d2d8a
--- /dev/null
+++ b/subprojects/bahaghari/tests/lib/hex.nix
@@ -0,0 +1,30 @@
+{ pkgs, lib }:
+
+pkgs.lib.runTests {
+  # Even though this is basically borrowing from nixpkgs', we still to test
+  # them for consistency.
+  testConvertToHex1 = {
+    expr = lib.hex.toHexString 534;
+    expected = "216";
+  };
+
+  testConvertToHex2 = {
+    expr = lib.hex.toHexString 864954;
+    expected = "D32BA";
+  };
+
+  testConvertToHex3 = {
+    expr = lib.hex.toHexString 293454837;
+    expected = "117DC3F5";
+  };
+
+  testCreateHexRange = {
+    expr = lib.hex.range 10 17;
+    expected = [ "A" "B" "C" "D" "E" "F" "10" "11" ];
+  };
+
+  testCreateHexWithHigherStart = {
+    expr = lib.hex.range 49 17;
+    expected = [ ];
+  };
+}