diff --git a/src/main/java/it/tdlight/tdlibsession/td/easy/AsyncTdEasy.java b/src/main/java/it/tdlight/tdlibsession/td/easy/AsyncTdEasy.java
index 6f03799..cbf2a3f 100644
--- a/src/main/java/it/tdlight/tdlibsession/td/easy/AsyncTdEasy.java
+++ b/src/main/java/it/tdlight/tdlibsession/td/easy/AsyncTdEasy.java
@@ -259,8 +259,8 @@ public class AsyncTdEasy {
 	public Mono<String> getOptionString(String name) {
 		return this
 				.<TdApi.OptionValue>sendDirectly(new TdApi.GetOption(name), DEFAULT_TIMEOUT, false)
-				.flatMap(MonoUtils::orElseThrow)
-				.flatMap((TdApi.OptionValue value) -> {
+				.<TdApi.OptionValue>handle(MonoUtils::orElseThrow)
+				.flatMap(value -> {
 			switch (value.getConstructor()) {
 				case OptionValueString.CONSTRUCTOR:
 					return Mono.just(((OptionValueString) value).value);
@@ -281,8 +281,8 @@ public class AsyncTdEasy {
 	public Mono<Long> getOptionInteger(String name) {
 		return this
 				.<TdApi.OptionValue>sendDirectly(new TdApi.GetOption(name), DEFAULT_TIMEOUT, false)
-				.flatMap(MonoUtils::orElseThrow)
-				.flatMap((TdApi.OptionValue value) -> {
+				.<TdApi.OptionValue>handle(MonoUtils::orElseThrow)
+				.flatMap(value -> {
 					switch (value.getConstructor()) {
 						case OptionValueInteger.CONSTRUCTOR:
 							return Mono.just(((OptionValueInteger) value).value);
@@ -303,8 +303,8 @@ public class AsyncTdEasy {
 	public Mono<Boolean> getOptionBoolean(String name) {
 		return this
 				.<TdApi.OptionValue>sendDirectly(new TdApi.GetOption(name), DEFAULT_TIMEOUT, false)
-				.flatMap(MonoUtils::orElseThrow)
-				.flatMap((TdApi.OptionValue value) -> {
+				.<TdApi.OptionValue>handle(MonoUtils::orElseThrow)
+				.flatMap(value -> {
 					switch (value.getConstructor()) {
 						case OptionValueBoolean.CONSTRUCTOR:
 							return Mono.just(((OptionValueBoolean) value).value);
diff --git a/src/main/java/it/tdlight/utils/MonoUtils.java b/src/main/java/it/tdlight/utils/MonoUtils.java
index d869e80..83b246d 100644
--- a/src/main/java/it/tdlight/utils/MonoUtils.java
+++ b/src/main/java/it/tdlight/utils/MonoUtils.java
@@ -16,7 +16,6 @@ import io.vertx.reactivex.core.streams.ReadStream;
 import io.vertx.reactivex.core.streams.WriteStream;
 import it.tdlight.jni.TdApi;
 import it.tdlight.jni.TdApi.Chat;
-import it.tdlight.jni.TdApi.Object;
 import it.tdlight.tdlibsession.td.TdError;
 import it.tdlight.tdlibsession.td.TdResult;
 import java.time.Duration;
@@ -86,11 +85,11 @@ public class MonoUtils {
 		}
 	}
 
-	public static <R extends TdApi.Object> Mono<R> orElseThrow(TdResult<R> value) {
+	public static <T extends TdApi.Object> void orElseThrow(TdResult<T> value, SynchronousSink<T> sink) {
 		if (value.succeeded()) {
-			return Mono.just(value.result());
+			sink.next(value.result());
 		} else {
-			return Mono.error(new TdError(value.cause().code, value.cause().message));
+			sink.error(new TdError(value.cause().code, value.cause().message));
 		}
 	}