diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/activity/UserSelectorActivity.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/activity/UserSelectorActivity.kt
index d048cb6ab..b562e4948 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/activity/UserSelectorActivity.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/activity/UserSelectorActivity.kt
@@ -109,8 +109,8 @@ class UserSelectorActivity : BaseActivity(), OnItemClickListener, LoaderManager.
 
     override fun onCreateLoader(id: Int, args: Bundle?): Loader<List<ParcelableUser>> {
         val accountKey = args?.getParcelable<UserKey>(EXTRA_ACCOUNT_KEY)!!
-        val query = args?.getString(EXTRA_QUERY).orEmpty()
-        val fromCache = args?.getBoolean(EXTRA_FROM_CACHE)
+        val query = args.getString(EXTRA_QUERY).orEmpty()
+        val fromCache = args.getBoolean(EXTRA_FROM_CACHE)
         if (!fromCache) {
             showProgress()
         }
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/adapter/StatusDetailsAdapter.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/adapter/StatusDetailsAdapter.kt
index 4961d3906..a7aa768e6 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/adapter/StatusDetailsAdapter.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/adapter/StatusDetailsAdapter.kt
@@ -117,7 +117,7 @@ class StatusDetailsAdapter(
         inflater = LayoutInflater.from(context)
         cardBackgroundColor = ThemeUtils.getCardBackgroundColor(context!!,
                 preferences[themeBackgroundOptionKey], preferences[themeBackgroundAlphaKey])
-        val listener = StatusAdapterLinkClickHandler<List<ParcelableStatus>>(context!!, preferences)
+        val listener = StatusAdapterLinkClickHandler<List<ParcelableStatus>>(context, preferences)
         listener.setAdapter(this)
         twidereLinkify = TwidereLinkify(listener)
     }
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/ColorPickerDialogFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/ColorPickerDialogFragment.kt
index aa62fa2e8..ef0dd7f8c 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/ColorPickerDialogFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/ColorPickerDialogFragment.kt
@@ -100,7 +100,7 @@ class ColorPickerDialogFragment : BaseDialogFragment(), DialogInterface.OnClickL
 
     override fun onSaveInstanceState(outState: Bundle) {
         if (controller != null) {
-            outState!!.putInt(EXTRA_COLOR, controller!!.color)
+            outState.putInt(EXTRA_COLOR, controller!!.color)
         }
         super.onSaveInstanceState(outState)
     }
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/UserFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/UserFragment.kt
index e1520072f..c87e45b75 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/UserFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/UserFragment.kt
@@ -667,7 +667,7 @@ class UserFragment : BaseFragment(), OnClickListener, OnLinkClickListener,
         actionBarShadowColor = 0xA0000000.toInt()
         val args = arguments
         val accountKey = args?.getParcelable<UserKey?>(EXTRA_ACCOUNT_KEY) ?: run {
-            activity?.finish()
+            activity.finish()
             return
         }
         val userKey = args.getParcelable<UserKey?>(EXTRA_USER_KEY)
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/filter/AddEditItemFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/filter/AddEditItemFragment.kt
index cf5d579a8..4fa212fea 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/filter/AddEditItemFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/filter/AddEditItemFragment.kt
@@ -253,7 +253,7 @@ class AddEditItemFragment : BaseDialogFragment() {
                         Toast.LENGTH_SHORT).show()
             } else {
                 val idWhere = Expression.equals(Filters._ID, rowId).sql
-                resolver?.update(uri, values, idWhere, null)
+                resolver.update(uri, values, idWhere, null)
             }
         } else {
             resolver?.insert(uri, values)
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/message/MessageNewConversationFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/message/MessageNewConversationFragment.kt
index bcfe87c1f..6aeef8430 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/message/MessageNewConversationFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/message/MessageNewConversationFragment.kt
@@ -238,7 +238,7 @@ class MessageNewConversationFragment : BaseFragment(), LoaderCallbacks<List<Parc
     }
 
     private fun createOrOpenConversation() {
-        val account = this.account ?: return
+        val account = this.account
         val context = context ?: return
         val activity = activity ?: return
         val selected = this.selectedRecipients
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/AbsStatusDialogFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/AbsStatusDialogFragment.kt
index b42de4699..0a411b3eb 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/AbsStatusDialogFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/AbsStatusDialogFragment.kt
@@ -80,7 +80,7 @@ abstract class AbsStatusDialogFragment : BaseDialogFragment() {
 
         val dialog = builder.create()
         dialog.onShow {
-            val context = it.context ?: return@onShow
+            val context = it.context
             it.applyTheme()
 
             val am = AccountManager.get(context)
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/StatusFragment.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/StatusFragment.kt
index 0cb6202d1..046d69706 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/StatusFragment.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/fragment/status/StatusFragment.kt
@@ -241,7 +241,7 @@ class StatusFragment : BaseFragment(), LoaderCallbacks<SingleResponse<Parcelable
         })
         adapter = StatusDetailsAdapter(this)
         layoutManager = StatusListLinearLayoutManager(context, recyclerView)
-        mItemDecoration = StatusDividerItemDecoration(context, adapter, layoutManager.orientation)?.apply {
+        mItemDecoration = StatusDividerItemDecoration(context, adapter, layoutManager.orientation).apply {
             recyclerView.addItemDecoration(this)
         }
         layoutManager.recycleChildrenOnDetach = true
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/loader/ExtensionsListLoader.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/loader/ExtensionsListLoader.kt
index 57c477d79..b00771bc4 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/loader/ExtensionsListLoader.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/loader/ExtensionsListLoader.kt
@@ -111,7 +111,7 @@ class ExtensionsListLoader(
 
         constructor(info: ApplicationInfo, pm: PackageManager) : this(
                 info.packageName,
-                info.loadLabel(pm) ?: info.packageName,
+                info.loadLabel(pm),
                 info.loadDescription(pm),
                 info.loadIcon(pm),
                 info.metaData?.getString(METADATA_KEY_EXTENSION_PERMISSIONS)?.split('|')?.filterNot(String::isEmpty)?.toTypedArray(),
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/preference/ColorPickerPreference.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/preference/ColorPickerPreference.kt
index 7eef95167..592a173fe 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/preference/ColorPickerPreference.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/preference/ColorPickerPreference.kt
@@ -122,7 +122,7 @@ class ColorPickerPreference(context: Context, attrs: AttributeSet? = null) :
             val preference = preference as ColorPickerPreference
             val alertDialog = dialog as AlertDialog
             alertDialog.applyTheme()
-            val windowView = alertDialog.window!!.decorView ?: return
+            val windowView = alertDialog.window!!.decorView
             controller = ColorPickerDialog.Controller(context, windowView)
             controller.setAlphaEnabled(preference.isAlphaSliderEnabled)
             for (presetColor in PRESET_COLORS) {
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/util/HttpClientFactory.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/util/HttpClientFactory.kt
index 74eb06138..f0a300d47 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/util/HttpClientFactory.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/util/HttpClientFactory.kt
@@ -103,9 +103,9 @@ object HttpClientFactory {
                 "[HOST]" -> url.host()
                 "[PORT]" -> url.port()
                 "[AUTHORITY]" -> url.authority()
-                "[PATH]" -> url.encodedPath()?.removePrefix("/").orEmpty()
+                "[PATH]" -> url.encodedPath().removePrefix("/")
                 "[/PATH]" -> url.encodedPath().orEmpty()
-                "[PATH_ENCODED]" -> url.encodedPath()?.removePrefix("/")?.urlEncoded()
+                "[PATH_ENCODED]" -> url.encodedPath().removePrefix("/").urlEncoded()
                 "[QUERY]" -> url.encodedQuery().orEmpty()
                 "[?QUERY]" -> url.encodedQuery()?.prefix("?").orEmpty()
                 "[QUERY_ENCODED]" -> url.encodedQuery()?.urlEncoded()
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/util/RecyclerViewScrollHandler.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/util/RecyclerViewScrollHandler.kt
index 8fe3da1a0..535426bb3 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/util/RecyclerViewScrollHandler.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/util/RecyclerViewScrollHandler.kt
@@ -34,7 +34,7 @@ class RecyclerViewScrollHandler<A>(contentListSupport: ContentListSupport<A>, vi
     }
 
     override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
-        val scrollState = recyclerView!!.scrollState
+        val scrollState = recyclerView.scrollState
         scrollHandler.handleScroll(dy, scrollState, oldState, RecyclerView.SCROLL_STATE_IDLE)
         oldState = scrollState
     }
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/util/glide/RoundedRectTransformation.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/util/glide/RoundedRectTransformation.kt
index 70d005bcb..e4be99d63 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/util/glide/RoundedRectTransformation.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/util/glide/RoundedRectTransformation.kt
@@ -46,7 +46,6 @@ class RoundedRectTransformation(
         val height = source.height
 
         val bitmap = bitmapPool.get(width, height, Bitmap.Config.ARGB_8888)
-                ?: Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
 
         val canvas = Canvas(bitmap)
         val paint = Paint()