diff --git a/modules/programs/difftastic.nix b/modules/programs/difftastic.nix
index f3997f53..ebb9b37b 100644
--- a/modules/programs/difftastic.nix
+++ b/modules/programs/difftastic.nix
@@ -67,11 +67,14 @@ in
     options = mkOption {
       type =
         with types;
-        attrsOf (oneOf [
-          str
-          int
-          bool
-        ]);
+        let
+          atom = oneOf [
+            str
+            int
+            bool
+          ];
+        in
+        attrsOf (either atom (listOf atom));
       default = { };
       example = {
         color = "dark";
diff --git a/tests/modules/programs/difftastic/difftastic-with-git-external-diff.nix b/tests/modules/programs/difftastic/difftastic-with-git-external-diff.nix
index 5434c9d9..dd7c24f2 100644
--- a/tests/modules/programs/difftastic/difftastic-with-git-external-diff.nix
+++ b/tests/modules/programs/difftastic/difftastic-with-git-external-diff.nix
@@ -8,6 +8,10 @@
     options = {
       color = "always";
       display = "side-by-side";
+      override = [
+        "*.mill:Scala"
+        "*.yuck:Emacs Lisp"
+      ];
     };
   };
 
@@ -17,7 +21,7 @@
     assertFileExists home-files/.config/git/config
     assertFileContains home-files/.config/git/config '[diff]'
     # Should have diff.external set
-    assertFileContains home-files/.config/git/config "external = \"@difftastic@/bin/difft '--color=always' '--display=side-by-side'\""
+    assertFileContains home-files/.config/git/config "external = \"@difftastic@/bin/difft '--color=always' '--display=side-by-side' '--override=*.mill:Scala' '--override=*.yuck:Emacs Lisp'\""
     # Should NOT have difftool config when diffToolMode is explicitly false
     assertFileNotRegex home-files/.config/git/config 'tool = "difftastic"'
     assertFileNotRegex home-files/.config/git/config '\[difftool "difftastic"\]'