diff --git a/electron/src/components/keymap/edit/keymap-edit.component.ts b/electron/src/components/keymap/edit/keymap-edit.component.ts
index 882393d6..bb115d3e 100644
--- a/electron/src/components/keymap/edit/keymap-edit.component.ts
+++ b/electron/src/components/keymap/edit/keymap-edit.component.ts
@@ -8,6 +8,7 @@ import 'rxjs/add/operator/do';
 import 'rxjs/add/operator/first';
 import 'rxjs/add/operator/map';
 import 'rxjs/add/operator/switchMap';
+import 'rxjs/add/operator/withLatestFrom';
 
 import { Keymap } from '../../../shared/config-serializer/config-items/keymap';
 import { UhkBuffer } from '../../../shared/config-serializer/uhk-buffer';
@@ -16,6 +17,7 @@ import { SvgKeyboardWrapComponent } from '../../../shared/components/svg/wrap';
 import { KeymapEditComponent as SharedKeymapEditComponent } from '../../../shared/components/keymap/edit';
 
 import { UhkDeviceService } from '../../../services/uhk-device.service';
+import { getUserConfiguration } from '../../../shared/store/reducers/user-configuration';
 
 @Component({
     selector: 'keymap-edit',
@@ -58,9 +60,10 @@ export class KeymapEditComponent extends SharedKeymapEditComponent {
         this.keymap$
             .first()
             .map(keymap => keymap.layers[currentLayer])
-            .map(layer => {
+            .withLatestFrom(this.store.let(getUserConfiguration()))
+            .map(([layer, userConfig]) => {
                 const uhkBuffer = new UhkBuffer();
-                layer.toBinary(uhkBuffer);
+                layer.toBinary(uhkBuffer, userConfig);
                 return uhkBuffer.getBufferContent();
             })
             .switchMap((buffer: Buffer) => this.uhkDevice.sendConfig(buffer))
@@ -76,9 +79,10 @@ export class KeymapEditComponent extends SharedKeymapEditComponent {
     private sendKeymap(): void {
         this.keymap$
             .first()
-            .map(keymap => {
+            .withLatestFrom(this.store.let(getUserConfiguration()))
+            .map(([keymap, userConfig]) => {
                 const uhkBuffer = new UhkBuffer();
-                keymap.toBinary(uhkBuffer);
+                keymap.toBinary(uhkBuffer, userConfig);
                 return uhkBuffer.getBufferContent();
             })
             .switchMap((buffer: Buffer) => this.uhkDevice.sendConfig(buffer))
diff --git a/shared/src/config-serializer/config-items/key-action/helper.ts b/shared/src/config-serializer/config-items/key-action/helper.ts
index 0f1c66c2..ac06bad5 100644
--- a/shared/src/config-serializer/config-items/key-action/helper.ts
+++ b/shared/src/config-serializer/config-items/key-action/helper.ts
@@ -7,7 +7,8 @@ import {
     PlayMacroAction,
     SwitchKeymapAction,
     SwitchLayerAction,
-    keyActionType
+    keyActionType,
+    UnresolvedSwitchKeymapAction
 } from './index';
 
 import { Macro } from '../macro';
@@ -39,7 +40,7 @@ export class Helper {
             case KeyActionId.SwitchLayerAction:
                 return new SwitchLayerAction().fromBinary(buffer);
             case KeyActionId.SwitchKeymapAction:
-                return new SwitchKeymapAction().fromBinary(buffer);
+                return new UnresolvedSwitchKeymapAction().fromBinary(buffer);
             case KeyActionId.MouseAction:
                 return new MouseAction().fromBinary(buffer);
             case KeyActionId.PlayMacroAction:
diff --git a/shared/src/config-serializer/config-items/key-action/key-action.ts b/shared/src/config-serializer/config-items/key-action/key-action.ts
index e4664e73..d33eb10a 100644
--- a/shared/src/config-serializer/config-items/key-action/key-action.ts
+++ b/shared/src/config-serializer/config-items/key-action/key-action.ts
@@ -1,5 +1,6 @@
 import { Macro } from '../macro';
 import { UhkBuffer } from '../../uhk-buffer';
+import { UserConfiguration } from '../user-configuration';
 
 export enum KeyActionId {
     NoneAction                   = 0,
@@ -44,7 +45,7 @@ export abstract class KeyAction {
         const keyActionId: number = KeyActionId[classname];
         if (keyActionId === KeyActionId.KeystrokeAction) {
             if (readKeyActionId < KeyActionId.KeystrokeAction || readKeyActionId > KeyActionId.LastKeystrokeAction) {
-                 throw `Invalid ${classname} first byte: ${readKeyActionId}`;
+                throw `Invalid ${classname} first byte: ${readKeyActionId}`;
             }
         } else if (readKeyActionId !== keyActionId) {
             throw `Invalid ${classname} first byte: ${readKeyActionId}`;
@@ -53,7 +54,7 @@ export abstract class KeyAction {
     }
 
     abstract toJsonObject(macros?: Macro[]): any;
-    abstract toBinary(buffer: UhkBuffer, macros?: Macro[]): any;
+    abstract toBinary(buffer: UhkBuffer, userConfiguration?: UserConfiguration): void;
 
     renameKeymap(oldAbbr: string, newAbbr: string): KeyAction {
         return this;
diff --git a/shared/src/config-serializer/config-items/key-action/play-macro-action.ts b/shared/src/config-serializer/config-items/key-action/play-macro-action.ts
index 7d9efd43..7e2cb221 100644
--- a/shared/src/config-serializer/config-items/key-action/play-macro-action.ts
+++ b/shared/src/config-serializer/config-items/key-action/play-macro-action.ts
@@ -2,6 +2,7 @@ import { assertUInt8 } from '../../assert';
 import { UhkBuffer } from '../../uhk-buffer';
 import { Macro } from '../macro';
 import { KeyAction, KeyActionId, keyActionType } from './key-action';
+import { UserConfiguration } from '../user-configuration';
 
 export class PlayMacroAction extends KeyAction {
 
@@ -40,9 +41,9 @@ export class PlayMacroAction extends KeyAction {
         };
     }
 
-    toBinary(buffer: UhkBuffer, macros: Macro[]) {
+    toBinary(buffer: UhkBuffer, userConfiguration: UserConfiguration) {
         buffer.writeUInt8(KeyActionId.PlayMacroAction);
-        buffer.writeUInt8(macros.findIndex(macro => macro.id === this.macroId));
+        buffer.writeUInt8(userConfiguration.macros.findIndex(macro => macro.id === this.macroId));
     }
 
     toString(): string {
diff --git a/shared/src/config-serializer/config-items/key-action/switch-keymap-action.ts b/shared/src/config-serializer/config-items/key-action/switch-keymap-action.ts
index 86163cec..9c87a7f4 100644
--- a/shared/src/config-serializer/config-items/key-action/switch-keymap-action.ts
+++ b/shared/src/config-serializer/config-items/key-action/switch-keymap-action.ts
@@ -1,6 +1,8 @@
+import { assertUInt8 } from '../../assert';
 import { UhkBuffer } from '../../uhk-buffer';
 import { Keymap } from '../keymap';
 import { KeyAction, KeyActionId, keyActionType } from './key-action';
+import { UserConfiguration } from '../user-configuration';
 
 export class SwitchKeymapAction extends KeyAction {
 
@@ -26,12 +28,6 @@ export class SwitchKeymapAction extends KeyAction {
         return this;
     }
 
-    fromBinary(buffer: UhkBuffer): SwitchKeymapAction {
-        this.readAndAssertKeyActionId(buffer);
-        this.keymapAbbreviation = buffer.readString();
-        return this;
-    }
-
     toJsonObject(): any {
         return {
             keyActionType: keyActionType.SwitchKeymapAction,
@@ -39,9 +35,10 @@ export class SwitchKeymapAction extends KeyAction {
         };
     }
 
-    toBinary(buffer: UhkBuffer) {
+    toBinary(buffer: UhkBuffer, userConfiguration: UserConfiguration): void {
+        const keymapIndex = userConfiguration.keymaps.findIndex(keymap => keymap.abbreviation === this.keymapAbbreviation);
         buffer.writeUInt8(KeyActionId.SwitchKeymapAction);
-        buffer.writeString(this.keymapAbbreviation);
+        buffer.writeUInt8(keymapIndex);
     }
 
     toString(): string {
@@ -55,3 +52,33 @@ export class SwitchKeymapAction extends KeyAction {
         return new SwitchKeymapAction(newAbbr);
     }
 }
+
+export class UnresolvedSwitchKeymapAction extends KeyAction {
+
+    @assertUInt8
+    keymapIndex: number;
+
+    constructor(keymapIndex?: number) {
+        super();
+        this.keymapIndex = keymapIndex;
+    }
+
+    fromBinary(buffer: UhkBuffer): UnresolvedSwitchKeymapAction {
+        buffer.readUInt8(); // Skip key action id
+        this.keymapIndex = buffer.readUInt8();
+        return this;
+    }
+
+    toBinary(buffer: UhkBuffer) {
+        buffer.writeUInt8(KeyActionId.SwitchKeymapAction);
+        buffer.writeUInt8(this.keymapIndex);
+    }
+
+    toJsonObject(): any {
+        throw new Error('UnresolvedSwitchKeymapAction cannot be serialized directly. Convert it to SwitchKeymapAction first.');
+    }
+
+    resolve(keymaps: Keymap[]): SwitchKeymapAction {
+        return new SwitchKeymapAction(keymaps[this.keymapIndex]);
+    }
+}
diff --git a/shared/src/config-serializer/config-items/keymap.ts b/shared/src/config-serializer/config-items/keymap.ts
index 038ca2f1..0bc621ca 100644
--- a/shared/src/config-serializer/config-items/keymap.ts
+++ b/shared/src/config-serializer/config-items/keymap.ts
@@ -2,6 +2,8 @@ import { UhkBuffer } from '../uhk-buffer';
 import { Layer } from './layer';
 import { Macro } from './macro';
 import { SwitchLayerAction, KeyAction } from './key-action';
+import { ConfigSerializer } from '../config-serializer';
+import { UserConfiguration } from './user-configuration';
 
 export class Keymap {
 
@@ -59,13 +61,13 @@ export class Keymap {
         };
     }
 
-    toBinary(buffer: UhkBuffer, macros?: Macro[]): void {
+    toBinary(buffer: UhkBuffer, userConfiguration: UserConfiguration): void {
         buffer.writeString(this.abbreviation);
         buffer.writeBoolean(this.isDefault);
         buffer.writeString(this.name);
         buffer.writeString(this.description);
         buffer.writeArray(this.layers, (uhkBuffer: UhkBuffer, layer: Layer) => {
-            layer.toBinary(uhkBuffer, macros);
+            layer.toBinary(uhkBuffer, userConfiguration);
         });
     }
 
diff --git a/shared/src/config-serializer/config-items/layer.ts b/shared/src/config-serializer/config-items/layer.ts
index 072d8674..33cf093f 100644
--- a/shared/src/config-serializer/config-items/layer.ts
+++ b/shared/src/config-serializer/config-items/layer.ts
@@ -1,6 +1,8 @@
 import { UhkBuffer } from '../uhk-buffer';
 import { Macro } from './macro';
 import { Module } from './module';
+import { UserConfiguration } from './user-configuration';
+import { ConfigSerializer } from '../config-serializer';
 
 export class Layer {
 
@@ -31,9 +33,9 @@ export class Layer {
         };
     }
 
-    toBinary(buffer: UhkBuffer, macros?: Macro[]): void {
+    toBinary(buffer: UhkBuffer, userConfiguration: UserConfiguration): void {
         buffer.writeArray(this.modules, (uhkBuffer: UhkBuffer, module: Module) => {
-            module.toBinary(uhkBuffer, macros);
+            module.toBinary(uhkBuffer, userConfiguration);
         });
     }
 
diff --git a/shared/src/config-serializer/config-items/module.ts b/shared/src/config-serializer/config-items/module.ts
index 267b3318..a626c37b 100644
--- a/shared/src/config-serializer/config-items/module.ts
+++ b/shared/src/config-serializer/config-items/module.ts
@@ -2,6 +2,7 @@ import { assertEnum, assertUInt8 } from '../assert';
 import { UhkBuffer } from '../uhk-buffer';
 import { Helper as KeyActionHelper, KeyAction, NoneAction, PlayMacroAction, SwitchKeymapAction } from './key-action';
 import { Macro } from './macro';
+import { UserConfiguration } from './user-configuration';
 
 enum PointerRole {
     none,
@@ -60,7 +61,7 @@ export class Module {
         };
     }
 
-    toBinary(buffer: UhkBuffer, macros?: Macro[]): void {
+    toBinary(buffer: UhkBuffer, userConfiguration: UserConfiguration): void {
         buffer.writeUInt8(this.id);
         buffer.writeUInt8(this.pointerRole);
 
@@ -74,7 +75,7 @@ export class Module {
         });
 
         buffer.writeArray(keyActions, (uhkBuffer: UhkBuffer, keyAction: KeyAction) => {
-            keyAction.toBinary(uhkBuffer, macros);
+            keyAction.toBinary(uhkBuffer, userConfiguration);
         });
     }
 
diff --git a/shared/src/config-serializer/config-items/user-configuration.ts b/shared/src/config-serializer/config-items/user-configuration.ts
index 819bef0b..a79a7cdb 100644
--- a/shared/src/config-serializer/config-items/user-configuration.ts
+++ b/shared/src/config-serializer/config-items/user-configuration.ts
@@ -3,6 +3,7 @@ import { UhkBuffer } from '../uhk-buffer';
 import { Keymap } from './keymap';
 import { Macro } from './macro';
 import { ModuleConfiguration } from './module-configuration';
+import { ConfigSerializer } from '../config-serializer';
 
 export class UserConfiguration {
 
@@ -40,6 +41,7 @@ export class UserConfiguration {
             return macro;
         });
         this.keymaps = buffer.readArray<Keymap>(uhkBuffer => new Keymap().fromBinary(uhkBuffer, this.macros));
+        ConfigSerializer.resolveSwitchKeymapActions(this.keymaps);
         return this;
     }
 
@@ -57,7 +59,7 @@ export class UserConfiguration {
         buffer.writeArray(this.moduleConfigurations);
         buffer.writeArray(this.macros);
         buffer.writeArray(this.keymaps, (uhkBuffer: UhkBuffer, keymap: Keymap) => {
-            keymap.toBinary(uhkBuffer, this.macros);
+            keymap.toBinary(uhkBuffer, this);
         });
     }
 
diff --git a/shared/src/config-serializer/config-serializer.ts b/shared/src/config-serializer/config-serializer.ts
new file mode 100644
index 00000000..181a8466
--- /dev/null
+++ b/shared/src/config-serializer/config-serializer.ts
@@ -0,0 +1,20 @@
+import { Keymap } from './config-items/keymap';
+import { UnresolvedSwitchKeymapAction } from './config-items/key-action';
+
+export namespace ConfigSerializer {
+
+    export function resolveSwitchKeymapActions(keymaps: Keymap[]) {
+        for (const keymap of keymaps) {
+            for (const layer of keymap.layers) {
+                for (const module of layer.modules) {
+                    for (let i = 0; i < module.keyActions.length; ++i) {
+                        const keyAction = module.keyActions[i];
+                        if (keyAction instanceof UnresolvedSwitchKeymapAction) {
+                            module.keyActions[i] = keyAction.resolve(keymaps);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/shared/src/config-serializer/index.ts b/shared/src/config-serializer/index.ts
new file mode 100644
index 00000000..456f542e
--- /dev/null
+++ b/shared/src/config-serializer/index.ts
@@ -0,0 +1 @@
+export { ConfigSerializer } from './config-serializer';