diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index c8effb2c..901c1bbe 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -14,7 +14,7 @@
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.VIBRATE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
-    <uses-permission-sdk-23 android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
+    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
 
     <application
         android:extractNativeLibs="true"
diff --git a/app/src/main/java/com/termux/app/ExtraKeysView.java b/app/src/main/java/com/termux/app/ExtraKeysView.java
index d0d6f91d..4c2694ce 100644
--- a/app/src/main/java/com/termux/app/ExtraKeysView.java
+++ b/app/src/main/java/com/termux/app/ExtraKeysView.java
@@ -427,11 +427,7 @@ public final class ExtraKeysView extends GridLayout {
 
                 LayoutParams param = new GridLayout.LayoutParams();
                 param.width = 0;
-                if(Build.VERSION.SDK_INT == Build.VERSION_CODES.LOLLIPOP) { // special handle api 21
-                    param.height = (int)(37.5 * getResources().getDisplayMetrics().density + 0.5); // 37.5 equal to R.id.viewpager layout_height / rows in DP
-                } else {
-                    param.height = 0;
-                }
+                param.height = 0;
                 param.setMargins(0, 0, 0, 0);
                 param.columnSpec = GridLayout.spec(col, GridLayout.FILL, 1.f);
                 param.rowSpec = GridLayout.spec(row, GridLayout.FILL, 1.f);
diff --git a/app/src/main/java/com/termux/app/TermuxActivity.java b/app/src/main/java/com/termux/app/TermuxActivity.java
index a84a7be7..0fe5b5df 100644
--- a/app/src/main/java/com/termux/app/TermuxActivity.java
+++ b/app/src/main/java/com/termux/app/TermuxActivity.java
@@ -188,18 +188,12 @@ public final class TermuxActivity extends Activity implements ServiceConnection
     }
 
     /** For processes to access shared internal storage (/sdcard) we need this permission. */
-    @TargetApi(Build.VERSION_CODES.M)
     public boolean ensureStoragePermissionGranted() {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-            if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
-                return true;
-            } else {
-                requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUESTCODE_PERMISSION_STORAGE);
-                return false;
-            }
-        } else {
-            // Always granted before Android 6.0.
+        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
             return true;
+        } else {
+            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUESTCODE_PERMISSION_STORAGE);
+            return false;
         }
     }
 
diff --git a/app/src/main/java/com/termux/app/TermuxService.java b/app/src/main/java/com/termux/app/TermuxService.java
index 3bc2583b..b17643fe 100644
--- a/app/src/main/java/com/termux/app/TermuxService.java
+++ b/app/src/main/java/com/termux/app/TermuxService.java
@@ -114,19 +114,17 @@ public final class TermuxService extends Service implements SessionChangedCallba
                 mWifiLock = wm.createWifiLock(WifiManager.WIFI_MODE_FULL_HIGH_PERF, EmulatorDebug.LOG_TAG);
                 mWifiLock.acquire();
 
-                if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-                    String packageName = getPackageName();
-                    if (!pm.isIgnoringBatteryOptimizations(packageName)) {
-                        Intent whitelist = new Intent();
-                        whitelist.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
-                        whitelist.setData(Uri.parse("package:" + packageName));
-                        whitelist.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+                String packageName = getPackageName();
+                if (!pm.isIgnoringBatteryOptimizations(packageName)) {
+                    Intent whitelist = new Intent();
+                    whitelist.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
+                    whitelist.setData(Uri.parse("package:" + packageName));
+                    whitelist.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 
-                        try {
-                            startActivity(whitelist);
-                        } catch (ActivityNotFoundException e) {
-                            Log.e(EmulatorDebug.LOG_TAG, "Failed to call ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS", e);
-                        }
+                    try {
+                        startActivity(whitelist);
+                    } catch (ActivityNotFoundException e) {
+                        Log.e(EmulatorDebug.LOG_TAG, "Failed to call ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS", e);
                     }
                 }
 
diff --git a/terminal-view/src/main/java/com/termux/view/TerminalView.java b/terminal-view/src/main/java/com/termux/view/TerminalView.java
index 9ec39804..95c13086 100644
--- a/terminal-view/src/main/java/com/termux/view/TerminalView.java
+++ b/terminal-view/src/main/java/com/termux/view/TerminalView.java
@@ -518,8 +518,7 @@ public final class TerminalView extends View {
                         mSelY2 = tmpY1;
                     }
 
-                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
-                        mActionMode.invalidateContentRect();
+                    mActionMode.invalidateContentRect();
                     invalidate();
                     break;
                 default:
@@ -875,41 +874,36 @@ public final class TerminalView extends View {
 
             };
 
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-                mActionMode = startActionMode(new ActionMode.Callback2() {
-                    @Override
-                    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
-                        return callback.onCreateActionMode(mode, menu);
-                    }
+            mActionMode = startActionMode(new ActionMode.Callback2() {
+                @Override
+                public boolean onCreateActionMode(ActionMode mode, Menu menu) {
+                    return callback.onCreateActionMode(mode, menu);
+                }
 
-                    @Override
-                    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
-                        return false;
-                    }
+                @Override
+                public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
+                    return false;
+                }
 
-                    @Override
-                    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
-                        return callback.onActionItemClicked(mode, item);
-                    }
+                @Override
+                public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
+                    return callback.onActionItemClicked(mode, item);
+                }
 
-                    @Override
-                    public void onDestroyActionMode(ActionMode mode) {
-                        // Ignore.
-                    }
-
-                    @Override
-                    public void onGetContentRect(ActionMode mode, View view, Rect outRect) {
-                        int x1 = Math.round(mSelX1 * mRenderer.mFontWidth);
-                        int x2 = Math.round(mSelX2 * mRenderer.mFontWidth);
-                        int y1 = Math.round((mSelY1 - mTopRow) * mRenderer.mFontLineSpacing);
-                        int y2 = Math.round((mSelY2 + 1 - mTopRow) * mRenderer.mFontLineSpacing);
-                        outRect.set(Math.min(x1, x2), y1, Math.max(x1, x2), y2);
-                    }
-                }, ActionMode.TYPE_FLOATING);
-            } else {
-                mActionMode = startActionMode(callback);
-            }
+                @Override
+                public void onDestroyActionMode(ActionMode mode) {
+                    // Ignore.
+                }
 
+                @Override
+                public void onGetContentRect(ActionMode mode, View view, Rect outRect) {
+                    int x1 = Math.round(mSelX1 * mRenderer.mFontWidth);
+                    int x2 = Math.round(mSelX2 * mRenderer.mFontWidth);
+                    int y1 = Math.round((mSelY1 - mTopRow) * mRenderer.mFontLineSpacing);
+                    int y2 = Math.round((mSelY2 + 1 - mTopRow) * mRenderer.mFontLineSpacing);
+                    outRect.set(Math.min(x1, x2), y1, Math.max(x1, x2), y2);
+                }
+            }, ActionMode.TYPE_FLOATING);
 
             invalidate();
         } else {