diff --git a/client/modules/IDE/actions/preferences.js b/client/modules/IDE/actions/preferences.js
index 4a3d0c9c..6314ac7c 100644
--- a/client/modules/IDE/actions/preferences.js
+++ b/client/modules/IDE/actions/preferences.js
@@ -44,7 +44,7 @@ export function decreaseIndentation() {
   };
 }
 
-export function updateIndentation() {
+export function updateIndentation(event) {
   const value = event.target.value;
   return {
     type: ActionTypes.UPDATE_INDENTATION,
diff --git a/client/modules/IDE/reducers/preferences.js b/client/modules/IDE/reducers/preferences.js
index 0f7b084c..dd5b6073 100644
--- a/client/modules/IDE/reducers/preferences.js
+++ b/client/modules/IDE/reducers/preferences.js
@@ -27,7 +27,7 @@ const preferences = (state = initialState, action) => {
       });
     case ActionTypes.UPDATE_FONTSIZE:
       return Object.assign({}, state, {
-        fontSize: action.value
+        fontSize: parseInt(action.value, 10)
       });
     case ActionTypes.INCREASE_INDENTATION:
       return Object.assign({}, state, {
@@ -39,7 +39,7 @@ const preferences = (state = initialState, action) => {
       });
     case ActionTypes.UPDATE_INDENTATION:
       return Object.assign({}, state, {
-        indentationAmount: action.value
+        indentationAmount: parseInt(action.value, 10)
       });
     case ActionTypes.INDENT_WITH_TAB:
       return Object.assign({}, state, {