diff --git a/osu.Game.Rulesets.Catch/CatchInputManager.cs b/osu.Game.Rulesets.Catch/CatchInputManager.cs
index 683724b7b8..2a913a77d3 100644
--- a/osu.Game.Rulesets.Catch/CatchInputManager.cs
+++ b/osu.Game.Rulesets.Catch/CatchInputManager.cs
@@ -10,7 +10,7 @@ namespace osu.Game.Rulesets.Catch
     public class CatchInputManager : DatabasedKeyBindingInputManager<CatchAction>
     {
         public CatchInputManager(RulesetInfo ruleset)
-            : base(ruleset, simultaneousMode: SimultaneousBindingMode.Unique)
+            : base(ruleset, 0, SimultaneousBindingMode.Unique)
         {
         }
     }
diff --git a/osu.Game.Rulesets.Osu/OsuInputManager.cs b/osu.Game.Rulesets.Osu/OsuInputManager.cs
index 06836994d2..a29b128e07 100644
--- a/osu.Game.Rulesets.Osu/OsuInputManager.cs
+++ b/osu.Game.Rulesets.Osu/OsuInputManager.cs
@@ -14,7 +14,7 @@ namespace osu.Game.Rulesets.Osu
 {
     public class OsuInputManager : DatabasedKeyBindingInputManager<OsuAction>
     {
-        public OsuInputManager(RulesetInfo ruleset) : base(ruleset, simultaneousMode: SimultaneousBindingMode.Unique)
+        public OsuInputManager(RulesetInfo ruleset) : base(ruleset, 0, SimultaneousBindingMode.Unique)
         {
 
         }
diff --git a/osu.Game/Input/Bindings/DatabasedKeyBindingInputManager.cs b/osu.Game/Input/Bindings/DatabasedKeyBindingInputManager.cs
index f739ba2a59..0a4fcf4389 100644
--- a/osu.Game/Input/Bindings/DatabasedKeyBindingInputManager.cs
+++ b/osu.Game/Input/Bindings/DatabasedKeyBindingInputManager.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Collections.Generic;
 using osu.Framework.Allocation;
 using osu.Framework.Input.Bindings;
@@ -17,7 +18,7 @@ namespace osu.Game.Input.Bindings
     {
         private readonly RulesetInfo ruleset;
 
-        private readonly int variant;
+        private readonly int? variant;
 
         private KeyBindingStore store;
 
@@ -29,11 +30,14 @@ namespace osu.Game.Input.Bindings
         /// <param name="ruleset">A reference to identify the current <see cref="Ruleset"/>. Used to lookup mappings. Null for global mappings.</param>
         /// <param name="variant">An optional variant for the specified <see cref="Ruleset"/>. Used when a ruleset has more than one possible keyboard layouts.</param>
         /// <param name="simultaneousMode">Specify how to deal with multiple matches of <see cref="KeyCombination"/>s and <see cref="T"/>s.</param>
-        protected DatabasedKeyBindingInputManager(RulesetInfo ruleset = null, int variant = 0, SimultaneousBindingMode simultaneousMode = SimultaneousBindingMode.None)
+        protected DatabasedKeyBindingInputManager(RulesetInfo ruleset = null, int? variant = null, SimultaneousBindingMode simultaneousMode = SimultaneousBindingMode.None)
             : base(simultaneousMode)
         {
             this.ruleset = ruleset;
             this.variant = variant;
+
+            if (ruleset != null && variant == null)
+                throw new InvalidOperationException($"{nameof(variant)} can not be null when a non-null {nameof(ruleset)} is provided.");
         }
 
         [BackgroundDependencyLoader]