diff --git a/src/main/java/io/appium/java_client/functions/ActionSupplier.java b/src/main/java/io/appium/java_client/functions/ActionSupplier.java
index 9554bf6ff..67ea8b888 100644
--- a/src/main/java/io/appium/java_client/functions/ActionSupplier.java
+++ b/src/main/java/io/appium/java_client/functions/ActionSupplier.java
@@ -20,6 +20,12 @@
 
 import java.util.function.Supplier;
 
+/**
+ * Represents a supplier of actions.
+ *
+ * @deprecated Use {@link Supplier} instead
+ */
+@Deprecated
 @FunctionalInterface
 public interface ActionSupplier<T extends PerformsActions<?>> extends Supplier<T> {
 }
diff --git a/src/main/java/io/appium/java_client/functions/AppiumFunction.java b/src/main/java/io/appium/java_client/functions/AppiumFunction.java
index de9069d37..1f45b32c1 100644
--- a/src/main/java/io/appium/java_client/functions/AppiumFunction.java
+++ b/src/main/java/io/appium/java_client/functions/AppiumFunction.java
@@ -28,7 +28,9 @@
  *
  * @param <F> The input type
  * @param <T> The return type
+ * @deprecated Use {@link java.util.function.Function} instead
  */
+@Deprecated
 @FunctionalInterface
 public interface AppiumFunction<F, T>  extends Function<F, T>, java.util.function.Function<F, T> {
 
diff --git a/src/main/java/io/appium/java_client/functions/ExpectedCondition.java b/src/main/java/io/appium/java_client/functions/ExpectedCondition.java
index 885952525..926577c53 100644
--- a/src/main/java/io/appium/java_client/functions/ExpectedCondition.java
+++ b/src/main/java/io/appium/java_client/functions/ExpectedCondition.java
@@ -23,7 +23,9 @@
  * with {@link java.util.function.Function}.
  *
  * @param <T> The return type
+ * @deprecated Use {@link org.openqa.selenium.support.ui.ExpectedCondition} instead
  */
+@Deprecated
 @FunctionalInterface
 public interface ExpectedCondition<T> extends org.openqa.selenium.support.ui.ExpectedCondition<T>,
         AppiumFunction<WebDriver, T> {
diff --git a/src/test/java/io/appium/java_client/android/AndroidAbilityToUseSupplierTest.java b/src/test/java/io/appium/java_client/android/AndroidAbilityToUseSupplierTest.java
index 5db7921a7..0fdd67661 100644
--- a/src/test/java/io/appium/java_client/android/AndroidAbilityToUseSupplierTest.java
+++ b/src/test/java/io/appium/java_client/android/AndroidAbilityToUseSupplierTest.java
@@ -1,7 +1,6 @@
 package io.appium.java_client.android;
 
 import io.appium.java_client.AppiumBy;
-import io.appium.java_client.functions.ActionSupplier;
 import io.appium.java_client.touch.offset.ElementOption;
 import org.junit.jupiter.api.Test;
 import org.openqa.selenium.By;
@@ -10,6 +9,7 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.function.Supplier;
 
 import static io.appium.java_client.TestUtils.getCenter;
 import static io.appium.java_client.touch.WaitOptions.waitOptions;
@@ -19,7 +19,7 @@
 
 public class AndroidAbilityToUseSupplierTest extends BaseAndroidTest {
 
-    private final ActionSupplier<AndroidTouchAction> horizontalSwipe = () -> {
+    private final Supplier<AndroidTouchAction> horizontalSwipe = () -> {
         driver.findElement(By.id("io.appium.android.apis:id/gallery"));
 
         WebElement gallery = driver.findElement(By.id("io.appium.android.apis:id/gallery"));
@@ -37,7 +37,7 @@ public class AndroidAbilityToUseSupplierTest extends BaseAndroidTest {
                 .release();
     };
 
-    private final ActionSupplier<AndroidTouchAction> verticalSwiping = () ->
+    private final Supplier<AndroidTouchAction> verticalSwiping = () ->
         new AndroidTouchAction(driver)
                 .press(element(driver.findElement(AppiumBy.accessibilityId("Gallery"))))
 
diff --git a/src/test/java/io/appium/java_client/android/AndroidFunctionTest.java b/src/test/java/io/appium/java_client/android/AndroidFunctionTest.java
index 79d327ae1..c8033cf9e 100644
--- a/src/test/java/io/appium/java_client/android/AndroidFunctionTest.java
+++ b/src/test/java/io/appium/java_client/android/AndroidFunctionTest.java
@@ -1,7 +1,5 @@
 package io.appium.java_client.android;
 
-import io.appium.java_client.functions.AppiumFunction;
-import io.appium.java_client.functions.ExpectedCondition;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -9,12 +7,14 @@
 import org.openqa.selenium.TimeoutException;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebElement;
+import org.openqa.selenium.support.ui.ExpectedCondition;
 import org.openqa.selenium.support.ui.FluentWait;
 import org.openqa.selenium.support.ui.Wait;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -27,16 +27,13 @@
 
 public class AndroidFunctionTest extends BaseAndroidTest {
 
-    private final AppiumFunction<WebDriver, List<WebElement>> searchingFunction = input -> {
+    private final Function<WebDriver, List<WebElement>> searchingFunction = input -> {
         List<WebElement> result = input.findElements(By.tagName("a"));
 
-        if (result.size() > 0) {
-            return result;
-        }
-        return null;
+        return result.isEmpty() ? null : result;
     };
 
-    private final AppiumFunction<Pattern, WebDriver> contextFunction = input -> {
+    private final Function<Pattern, WebDriver> contextFunction = input -> {
         Set<String> contexts = driver.getContextHandles();
         String current = driver.getContext();
         contexts.forEach(context -> {
@@ -51,7 +48,7 @@ public class AndroidFunctionTest extends BaseAndroidTest {
         return null;
     };
 
-    private final AppiumFunction<List<WebElement>, List<WebElement>> filteringFunction = input -> {
+    private final Function<List<WebElement>, List<WebElement>> filteringFunction = input -> {
         final List<WebElement> result = new ArrayList<>();
         input.forEach(element -> {
             if (element.getText().equals("Hello World! - 1")) {
@@ -59,10 +56,7 @@ public class AndroidFunctionTest extends BaseAndroidTest {
             }
         });
 
-        if (result.size() > 0) {
-            return result;
-        }
-        return null;
+        return result.isEmpty() ? null : result;
     };
 
     @BeforeAll
@@ -80,8 +74,7 @@ public void setUp() {
 
     @Test
     public void complexWaitingTestWithPreCondition() {
-        AppiumFunction<Pattern, List<WebElement>> compositeFunction =
-                searchingFunction.compose(contextFunction);
+        Function<Pattern, List<WebElement>> compositeFunction = searchingFunction.compose(contextFunction);
 
         Wait<Pattern> wait = new FluentWait<>(Pattern.compile("WEBVIEW"))
                 .withTimeout(ofSeconds(30));
@@ -94,7 +87,7 @@ public void complexWaitingTestWithPreCondition() {
     @Test public void complexWaitingTestWithPostConditions() {
         final List<Boolean> calls = new ArrayList<>();
 
-        AppiumFunction<Pattern, WebDriver> waitingForContext = input -> {
+        Function<Pattern, WebDriver> waitingForContext = input -> {
             WebDriver result = contextFunction.apply(input);
             if (result != null) {
                 calls.add(true);
@@ -102,7 +95,7 @@ public void complexWaitingTestWithPreCondition() {
             return result;
         };
 
-        AppiumFunction<Pattern, List<WebElement>> compositeFunction = waitingForContext
+        Function<Pattern, List<WebElement>> compositeFunction = waitingForContext
                 .andThen((ExpectedCondition<List<WebElement>>) input -> {
                     List<WebElement> result = searchingFunction.apply(input);
                     if (result != null) {
@@ -110,7 +103,7 @@ public void complexWaitingTestWithPreCondition() {
                     }
                     return result;
                 })
-                .andThen((AppiumFunction<List<WebElement>, List<WebElement>>) input -> {
+                .andThen(input -> {
                     List<WebElement> result = filteringFunction.apply(input);
                     if (result != null) {
                         calls.add(true);