diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 2e81bdf..f1253b4 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -338,6 +338,8 @@
             <!-- If true, use functionalTextColor instead of ketTextColor to drawing the label on
                  the key -->
             <flag name="followFunctionalTextColor" value="0x80000" />
+            <!-- Keep aspect ratio of key background. -->
+            <flag name="keepBackgroundAspectRatio" value="0x100000" />
             <!-- If true, disable keyHintLabel. -->
             <flag name="disableKeyHintLabel" value="0x40000000" />
             <!-- If true, disable additionalMoreKeys. -->
diff --git a/java/res/values/themes-lxx-dark.xml b/java/res/values/themes-lxx-dark.xml
index 76e9d33..5b26813 100644
--- a/java/res/values/themes-lxx-dark.xml
+++ b/java/res/values/themes-lxx-dark.xml
@@ -114,6 +114,7 @@
         <item name="android:background">@android:color/transparent</item>
         <item name="keyBackground">@drawable/btn_keyboard_key_popup_action_lxx_dark</item>
         <item name="divider">@null</item>
+        <item name="keyLabelFlags">keepBackgroundAspectRatio</item>
     </style>
     <style
         name="SuggestionStripView.LXX_Dark"
diff --git a/java/res/values/themes-lxx-light.xml b/java/res/values/themes-lxx-light.xml
index 5cd8417..f607807 100644
--- a/java/res/values/themes-lxx-light.xml
+++ b/java/res/values/themes-lxx-light.xml
@@ -114,6 +114,7 @@
         <item name="android:background">@android:color/transparent</item>
         <item name="keyBackground">@drawable/btn_keyboard_key_popup_action_lxx_light</item>
         <item name="divider">@null</item>
+        <item name="keyLabelFlags">keepBackgroundAspectRatio</item>
     </style>
     <style
         name="SuggestionStripView.LXX_Light"
diff --git a/java/res/xml-sw600dp/key_styles_enter.xml b/java/res/xml-sw600dp/key_styles_enter.xml
index d066d2d..63ef2f8 100644
--- a/java/res/xml-sw600dp/key_styles_enter.xml
+++ b/java/res/xml-sw600dp/key_styles_enter.xml
@@ -80,13 +80,27 @@
         </default>
     </switch>
     <!-- Enter key style -->
-    <key-style
-        latin:styleName="defaultEnterKeyStyle"
-        latin:keySpec="!icon/enter_key|!code/key_enter"
-        latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor"
-        latin:keyActionFlags="noKeyPreview"
-        latin:backgroundType="action"
-        latin:parentStyle="navigateMoreKeysStyle" />
+    <switch>
+        <case latin:keyboardTheme="ICS|KLP">
+            <key-style
+                latin:styleName="defaultEnterKeyStyle"
+                latin:keySpec="!icon/enter_key|!code/key_enter"
+                latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action"
+                latin:parentStyle="navigateMoreKeysStyle" />
+        </case>
+        <!-- keyboardTheme="LXXLight|LXXDark" -->
+        <default>
+            <key-style
+                latin:styleName="defaultEnterKeyStyle"
+                latin:keySpec="!icon/enter_key|!code/key_enter"
+                latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor|keepBackgroundAspectRatio"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action"
+                latin:parentStyle="navigateMoreKeysStyle" />
+        </default>
+    </switch>
     <include latin:keyboardLayout="@xml/key_styles_actions" />
     <switch>
         <!-- Shift + Enter in textMultiLine field. -->
diff --git a/java/res/xml/key_styles_common.xml b/java/res/xml/key_styles_common.xml
index 43ee26b..b36ddf2 100644
--- a/java/res/xml/key_styles_common.xml
+++ b/java/res/xml/key_styles_common.xml
@@ -80,11 +80,24 @@
         latin:keyActionFlags="isRepeatable|noKeyPreview"
         latin:backgroundType="functional" />
     <!-- emojiKeyStyle must be defined before including @xml/key_syles_enter. -->
-    <key-style
-        latin:styleName="emojiKeyStyle"
-        latin:keySpec="!icon/emoji_action_key|!code/key_emoji"
-        latin:keyActionFlags="noKeyPreview"
-        latin:backgroundType="action" />
+    <switch>
+        <case latin:keyboardTheme="ICS|KLP">
+            <key-style
+                latin:styleName="emojiKeyStyle"
+                latin:keySpec="!icon/emoji_action_key|!code/key_emoji"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action" />
+        </case>
+        <!-- keyboardTheme="LXXLight|LXXDark" -->
+        <default>
+            <key-style
+                latin:styleName="emojiKeyStyle"
+                latin:keySpec="!icon/emoji_action_key|!code/key_emoji"
+                latin:keyLabelFlags="keepBackgroundAspectRatio"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action" />
+        </default>
+    </switch>
     <include
         latin:keyboardLayout="@xml/key_styles_enter" />
     <!-- TODO: Currently there is no way to specify icon alignment per theme. -->
diff --git a/java/res/xml/key_styles_enter.xml b/java/res/xml/key_styles_enter.xml
index d6d01b8..564f465 100644
--- a/java/res/xml/key_styles_enter.xml
+++ b/java/res/xml/key_styles_enter.xml
@@ -212,13 +212,27 @@
         </default>
     </switch>
     <!-- Enter key style -->
-    <key-style
-        latin:styleName="defaultEnterKeyStyle"
-        latin:keySpec="!icon/enter_key|!code/key_enter"
-        latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor"
-        latin:keyActionFlags="noKeyPreview"
-        latin:backgroundType="action"
-        latin:parentStyle="navigateMoreKeysStyle" />
+    <switch>
+        <case latin:keyboardTheme="ICS|KLP">
+            <key-style
+                latin:styleName="defaultEnterKeyStyle"
+                latin:keySpec="!icon/enter_key|!code/key_enter"
+                latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action"
+                latin:parentStyle="navigateMoreKeysStyle" />
+        </case>
+        <!-- keyboardTheme="LXXLight|LXXDark" -->
+        <default>
+            <key-style
+                latin:styleName="defaultEnterKeyStyle"
+                latin:keySpec="!icon/enter_key|!code/key_enter"
+                latin:keyLabelFlags="preserveCase|autoXScale|followKeyLabelRatio|followFunctionalTextColor|keepBackgroundAspectRatio"
+                latin:keyActionFlags="noKeyPreview"
+                latin:backgroundType="action"
+                latin:parentStyle="navigateMoreKeysStyle" />
+        </default>
+    </switch>
     <include latin:keyboardLayout="@xml/key_styles_actions" />
     <switch>
         <!-- Shift + Enter in textMultiLine field. -->