diff --git a/modules/programs/qutebrowser.nix b/modules/programs/qutebrowser.nix
index b6cc41ea..9c3ad6a8 100644
--- a/modules/programs/qutebrowser.nix
+++ b/modules/programs/qutebrowser.nix
@@ -9,7 +9,7 @@ let
   formatLine = o: n: v:
     let
       formatValue = v:
-        if builtins.isNull v then
+        if v == null then
           "None"
         else if builtins.isBool v then
           (if v then "True" else "False")
@@ -29,7 +29,10 @@ let
   formatKeyBindings = m: b:
     let
       formatKeyBinding = m: k: c:
-        ''config.bind("${k}", "${escape [ ''"'' ] c}", mode="${m}")'';
+        if c == null then
+          ''config.unbind("${k}", mode="${m}")''
+        else
+          ''config.bind("${k}", "${escape [ ''"'' ] c}", mode="${m}")'';
     in concatStringsSep "\n" (mapAttrsToList (formatKeyBinding m) b);
 
   formatQuickmarks = n: s: "${n} ${s}";
@@ -131,7 +134,7 @@ in {
     };
 
     keyBindings = mkOption {
-      type = with types; attrsOf (attrsOf (separatedString " ;; "));
+      type = with types; attrsOf (attrsOf (nullOr (separatedString " ;; ")));
       default = { };
       description = ''
         Key bindings mapping keys to commands in different modes. This setting
diff --git a/tests/modules/programs/qutebrowser/keybindings.nix b/tests/modules/programs/qutebrowser/keybindings.nix
index 00e730ef..37ccfeba 100644
--- a/tests/modules/programs/qutebrowser/keybindings.nix
+++ b/tests/modules/programs/qutebrowser/keybindings.nix
@@ -8,6 +8,7 @@
 
     keyBindings = {
       normal = {
+        ":" = null;
         "<Ctrl-v>" = "spawn mpv {url}";
         ",l" = ''config-cycle spellcheck.languages ["en-GB"] ["en-US"]'';
         "<F1>" = lib.mkMerge [
@@ -35,6 +36,7 @@
           config.load_autoconfig(False)
           c.bindings.default = {}
           config.bind(",l", "config-cycle spellcheck.languages [\"en-GB\"] [\"en-US\"]", mode="normal")
+          config.unbind(":", mode="normal")
           config.bind("<Ctrl-v>", "spawn mpv {url}", mode="normal")
           config.bind("<F1>", "config-cycle tabs.show never always ;; config-cycle statusbar.show in-mode always ;; config-cycle scrolling.bar never always", mode="normal")
           config.bind("<Ctrl-y>", "prompt-yes", mode="prompt")''