diff --git a/build.gradle b/build.gradle
index d57de07d218aa44cd46732035b9bb13e11079ea6..2a070856a328c440e15b335fb14858925fb434a3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -90,7 +90,7 @@ android {
     compileSdkVersion 29
 
     defaultConfig {
-        minSdkVersion 24
+        minSdkVersion 21
         targetSdkVersion 29
         versionCode 42024
         versionName "2.10.3-beta"
diff --git a/src/main/java/eu/siacs/conversations/ui/widget/DialpadView.java b/src/main/java/eu/siacs/conversations/ui/widget/DialpadView.java
index 5b16dce17230ede9937db7e61c65c242a9018a7b..fa4d46ec5781fc499cad2da56e9eb77908c858d9 100644
--- a/src/main/java/eu/siacs/conversations/ui/widget/DialpadView.java
+++ b/src/main/java/eu/siacs/conversations/ui/widget/DialpadView.java
@@ -26,7 +26,7 @@ import eu.siacs.conversations.R;
 
 public class DialpadView extends ConstraintLayout implements View.OnClickListener {
 
-    protected java.util.function.Consumer<String> clickConsumer = null;
+    protected Consumer<String> clickConsumer = null;
 
     public DialpadView(Context context) {
         super(context);
@@ -43,7 +43,7 @@ public class DialpadView extends ConstraintLayout implements View.OnClickListene
         init();
     }
 
-    public void setClickConsumer(java.util.function.Consumer<String> clickConsumer) {
+    public void setClickConsumer(Consumer<String> clickConsumer) {
         this.clickConsumer = clickConsumer;
     }
 
@@ -72,4 +72,8 @@ public class DialpadView extends ConstraintLayout implements View.OnClickListene
         clickConsumer.accept(v.getTag().toString());
     }
 
+	// Based on java.util.function.Consumer to avoid Android 24 dependency
+	public interface Consumer<T> {
+		void accept(T t);
+	}
 }