diff --git a/GodotGooglePlayBilling.gdap b/GodotGooglePlayBilling.gdap
index b6fddfd..b50d3e8 100644
--- a/GodotGooglePlayBilling.gdap
+++ b/GodotGooglePlayBilling.gdap
@@ -5,4 +5,4 @@ binary_type="local"
 binary="GodotGooglePlayBilling.1.1.2.release.aar"
 
 [dependencies]
-remote=["com.android.billingclient:billing:4.0.0"]
+remote=["com.android.billingclient:billing:5.4.0"]
diff --git a/godot-google-play-billing/build.gradle b/godot-google-play-billing/build.gradle
index 8e987ea..656634b 100644
--- a/godot-google-play-billing/build.gradle
+++ b/godot-google-play-billing/build.gradle
@@ -6,12 +6,12 @@ ext.pluginVersionCode = 4
 ext.pluginVersionName = "1.1.2"
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
     buildToolsVersion "30.0.3"
 
     defaultConfig {
         minSdkVersion 18
-        targetSdkVersion 30 
+        targetSdkVersion 31
         versionCode pluginVersionCode
         versionName pluginVersionName
     }
@@ -25,6 +25,6 @@ android {
 
 dependencies {
     implementation "androidx.legacy:legacy-support-v4:1.0.0"
-    implementation 'com.android.billingclient:billing:4.0.0'
+    implementation 'com.android.billingclient:billing:5.2.0'
     compileOnly fileTree(dir: 'libs', include: ['godot-lib*.aar'])
 }
diff --git a/godot-google-play-billing/src/main/java/org/godotengine/godot/plugin/googleplaybilling/GodotGooglePlayBilling.java b/godot-google-play-billing/src/main/java/org/godotengine/godot/plugin/googleplaybilling/GodotGooglePlayBilling.java
index a519223..1baa7dd 100644
--- a/godot-google-play-billing/src/main/java/org/godotengine/godot/plugin/googleplaybilling/GodotGooglePlayBilling.java
+++ b/godot-google-play-billing/src/main/java/org/godotengine/godot/plugin/googleplaybilling/GodotGooglePlayBilling.java
@@ -35,6 +35,7 @@
 import org.godotengine.godot.plugin.GodotPlugin;
 import org.godotengine.godot.plugin.SignalInfo;
 import org.godotengine.godot.plugin.googleplaybilling.utils.GooglePlayBillingUtils;
+import org.godotengine.godot.plugin.UsedByGodot;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -91,15 +92,16 @@ public void startConnection() {
 	public void endConnection() {
 		billingClient.endConnection();
 	}
-
+	@UsedByGodot
 	public boolean isReady() {
 		return this.billingClient.isReady();
 	}
-
+	@UsedByGodot
 	public int getConnectionState() {
 		return billingClient.getConnectionState();
 	}
 
+	@UsedByGodot
 	public void queryPurchases(String type) {
 		billingClient.queryPurchasesAsync(type, new PurchasesResponseListener() {
 			@Override
@@ -118,7 +120,7 @@ public void onQueryPurchasesResponse(BillingResult billingResult,
 			}
 		});
 	}
-
+	@UsedByGodot
 	public void querySkuDetails(final String[] list, String type) {
 		List<String> skuList = Arrays.asList(list);
 
@@ -141,7 +143,7 @@ public void onSkuDetailsResponse(BillingResult billingResult,
 			}
 		});
 	}
-
+	@UsedByGodot
 	public void acknowledgePurchase(final String purchaseToken) {
 		AcknowledgePurchaseParams acknowledgePurchaseParams =
 				AcknowledgePurchaseParams.newBuilder()
@@ -159,6 +161,7 @@ public void onAcknowledgePurchaseResponse(BillingResult billingResult) {
 		});
 	}
 
+	@UsedByGodot
 	public void consumePurchase(String purchaseToken) {
 		ConsumeParams consumeParams = ConsumeParams.newBuilder()
 											  .setPurchaseToken(purchaseToken)
@@ -189,7 +192,7 @@ public void onBillingSetupFinished(BillingResult billingResult) {
 	public void onBillingServiceDisconnected() {
 		emitSignal("disconnected");
 	}
-
+	@UsedByGodot
 	public Dictionary confirmPriceChange(String sku) {
 		if (!skuDetailsCache.containsKey(sku)) {
 			Dictionary returnValue = new Dictionary();
@@ -210,12 +213,12 @@ public Dictionary confirmPriceChange(String sku) {
 		returnValue.put("status", 0); // OK = 0
 		return returnValue;
 	}
-
+	@UsedByGodot
 	public Dictionary purchase(String sku) {
 		return purchaseInternal("", sku, 
 			BillingFlowParams.ProrationMode.UNKNOWN_SUBSCRIPTION_UPGRADE_DOWNGRADE_POLICY);
 	}
-
+	@UsedByGodot
 	public Dictionary updateSubscription(String oldToken, String sku, int prorationMode) {
 		return purchaseInternal(oldToken, sku, prorationMode);
 	}
@@ -258,11 +261,12 @@ private Dictionary purchaseInternal(String oldToken, String sku, int prorationMo
 		}
 
 		return returnValue;
-	}	
+	}
+	@UsedByGodot
 	public void setObfuscatedAccountId(String accountId) {
 		obfuscatedAccountId = accountId;
 	}
-
+	@UsedByGodot
 	public void setObfuscatedProfileId(String profileId) {
 		obfuscatedProfileId = profileId;
 	}