diff --git a/buildSrc/src/main/kotlin/Dependencies.kt b/buildSrc/src/main/kotlin/Dependencies.kt
index e80e48a..c2ff1aa 100644
--- a/buildSrc/src/main/kotlin/Dependencies.kt
+++ b/buildSrc/src/main/kotlin/Dependencies.kt
@@ -5,8 +5,8 @@ object Versions {
     const val ANDROID_GRADLE_PLUGIN = "7.4.2"
     const val JUNIT = "4.13.2"
     const val ROBOLECTRIC = "4.3"
-    const val MOCKITO = "3.12.4"
-    const val MOCKITO_KOTILN = "3.2.0"
+    const val MOCKITO = "4.11.0"
+    const val MOCKITO_KOTLIN = "4.1.0"
     const val CORE_KTX = "1.10.1"
     const val FRAGMENT_KTX = "1.2.4"
     const val DETEKT_RUNTIME = "1.23.1"
@@ -15,7 +15,7 @@ object Versions {
 
     const val COMPILE_SDK_VERSION = 33
     const val TARGET_SDK_VERSION = 33
-    const val MIN_SDK_VERSION = 21
+    const val MIN_SDK_VERSION = 23
 
     private const val MAJOR = 0
     private const val MINOR = 6
@@ -34,7 +34,7 @@ object Libs {
     const val JUNIT = "junit:junit:${Versions.JUNIT}"
     const val ROBOLECTRIC = "org.robolectric:robolectric:${Versions.ROBOLECTRIC}"
     const val MOCKITO = "org.mockito:mockito-core:${Versions.MOCKITO}"
-    const val MOCKITO_KOTLIN = "org.mockito.kotlin:mockito-kotlin:${Versions.MOCKITO_KOTILN}"
+    const val MOCKITO_KOTLIN = "org.mockito.kotlin:mockito-kotlin:${Versions.MOCKITO_KOTLIN}"
     const val CORE_KTX = "androidx.core:core-ktx:${Versions.CORE_KTX}"
     const val KOTLIN_TESTS = "org.jetbrains.kotlin:kotlin-test:${Versions.KOTLIN}"
     const val FRAGMENT_KTX = "androidx.fragment:fragment-ktx:${Versions.FRAGMENT_KTX}"
diff --git a/library/src/main/java/com/vinted/coper/CoperFragment.kt b/library/src/main/java/com/vinted/coper/CoperFragment.kt
index 6b730f9..fa9feae 100644
--- a/library/src/main/java/com/vinted/coper/CoperFragment.kt
+++ b/library/src/main/java/com/vinted/coper/CoperFragment.kt
@@ -1,6 +1,5 @@
 package com.vinted.coper
 
-import android.os.Build
 import android.os.Bundle
 import android.util.Log
 import androidx.annotation.VisibleForTesting
@@ -101,7 +100,7 @@ internal class CoperFragment : Fragment() {
                 getDeniedPermissionsResult(denied)
             } else {
                 getPermissionsResult(
-                    permissionChecks = requestPermissionsByVersion(denied.toTypedArray()),
+                    permissionChecks = requestPermissionsAsync(denied.toTypedArray()).await(),
                     grantedPermissions = granted,
                     isSecondTime = true
                 )
@@ -122,21 +121,6 @@ internal class CoperFragment : Fragment() {
         return PermissionResult.Denied(deniedPermissions)
     }
 
-    // On devices with lower sdk than 23, there is no requesting permissions.
-    private suspend fun requestPermissionsByVersion(
-        permissions: Array<out String>
-    ): List<PermissionCheckResult> {
-        return if (isDeviceSdkAtLeastMarshmallow()) {
-            requestPermissionsAsync(permissions).await()
-        } else {
-            permissions.map { PermissionCheckResult.Denied(it) }
-        }
-    }
-
-    private fun isDeviceSdkAtLeastMarshmallow(): Boolean {
-        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
-    }
-
     private fun requestPermissionsAsync(
         permissions: Array<out String>
     ): Deferred<List<PermissionCheckResult>> {
@@ -237,13 +221,7 @@ internal class CoperFragment : Fragment() {
             fun of(permissionResult: Int, permission: String): PermissionCheckResult {
                 return when (permissionResult) {
                     PermissionChecker.PERMISSION_GRANTED -> Granted(permission)
-                    PermissionChecker.PERMISSION_DENIED,
-                    PermissionChecker.PERMISSION_DENIED_APP_OP -> Denied(permission)
-                    else -> {
-                        val message = "Not expected permission result: $permissionResult " +
-                                "for $permission"
-                        throw IllegalStateException(message)
-                    }
+                    else -> Denied(permission)
                 }
             }
         }
diff --git a/library/src/test/java/com/vinted/coper/CoperImplTest.kt b/library/src/test/java/com/vinted/coper/CoperImplTest.kt
index ab53025..179b92f 100644
--- a/library/src/test/java/com/vinted/coper/CoperImplTest.kt
+++ b/library/src/test/java/com/vinted/coper/CoperImplTest.kt
@@ -46,7 +46,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun request_responseIsSuccessful() = runTest {
         val response = fixture.request("test")
 
@@ -54,7 +54,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun request_permissionsIsGranted_grantedListConsistOfThisPermission() = runTest {
         val permissionName = "granted"
         shadowOf(activity).grantPermissions(permissionName)
@@ -66,7 +66,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun request_twoPermissionsIsGranted_grantedListConsistOfThisPermissions() = runTest {
         val firstPermission = "granted"
         val secondPermission = "granted2"
@@ -78,18 +78,6 @@ class CoperImplTest {
         assertEquals(listOf(firstPermission, secondPermission), response.grantedPermissions)
     }
 
-    @Test
-    @Config(sdk = [21])
-    fun request_sdkUnder23AndPermissionsDenied_permissionResultDeniedWaitingResult() = runTest {
-        val permission = "denied"
-        shadowOf(activity).denyPermissions(permission)
-
-        val response = fixture.request(permission)
-
-        assertTrue(response.isDenied())
-        assertEquals(listOf(permission), response.getAllDeniedPermissions())
-    }
-
     @Test
     fun request_permissionsIsDeniedRationale_permissionDeniedRationaleResult() = runTest {
         val permissionName = "denied"
@@ -658,7 +646,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun isPermissionsGranted_permissionsNotGranted_returnsFalse() = runTest {
         val permission = "not_granted"
         shadowOf(activity).denyPermissions(permission)
@@ -669,7 +657,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun isPermissionsGranted_permissionsGranted_returnsTrue() = runTest {
         val permission = "granted"
         shadowOf(activity).grantPermissions(permission)
@@ -719,7 +707,7 @@ class CoperImplTest {
     }
 
     @Test
-    @Config(sdk = [21, 23, 27])
+    @Config(sdk = [23, 27])
     fun request_runOnPausingDispatcher_responseIsSuccessful() = runTest {
         val isCancelled = fixture.getFragmentSafely().lifecycleScope.launchWhenCreated {
             fixture.request("test")