diff --git a/src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java b/src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java
index 968ffe094..a5ce6cde3 100644
--- a/src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java
+++ b/src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java
@@ -22,6 +22,7 @@ import io.netty.handler.ssl.IdentityCipherSuiteFilter;
 import io.netty.handler.ssl.JdkSslContext;
 import io.netty.handler.timeout.ReadTimeoutHandler;
 import io.netty.handler.timeout.WriteTimeoutHandler;
+import reactor.core.Exceptions;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.FluxProcessor;
 import reactor.core.publisher.Mono;
@@ -467,12 +468,12 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 			searchRequest.scroll(scrollTimeout);
 		}
 
-		Sinks.Many<ActionRequest> request = Sinks.many().unicast().onBackpressureBuffer();
+		Sinks.Many<ActionRequest> requests = Sinks.many().unicast().onBackpressureBuffer();
 
 		FluxProcessor<SearchResponse, SearchResponse> inbound = FluxProcessor
 				.fromSink(Sinks.many().unicast().onBackpressureBuffer());
 
-		Flux<SearchResponse> exchange = request.asFlux().flatMap(it -> {
+		Flux<SearchResponse> exchange = requests.asFlux().flatMap(it -> {
 
 			if (it instanceof SearchRequest) {
 				return sendRequest((SearchRequest) it, requestCreator.search(), SearchResponse.class, headers);
@@ -483,8 +484,8 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 						.flatMap(discard -> Flux.empty());
 			}
 
-			throw new IllegalArgumentException(
-					String.format("Cannot handle '%s'. Please make sure to use a 'SearchRequest' or 'SearchScrollRequest'.", it));
+			return Flux.error(new IllegalArgumentException(String
+					.format("Cannot handle '%s'. Please make sure to use a 'SearchRequest' or 'SearchScrollRequest'.", it)));
 		});
 
 		return Flux.usingWhen(Mono.fromSupplier(ScrollState::new),
@@ -497,7 +498,7 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 						if (isEmpty(searchResponse.getHits())) {
 
 							inbound.onComplete();
-							request.emitComplete();
+							requests.tryEmitComplete();
 
 						} else {
 
@@ -505,7 +506,7 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 
 							SearchScrollRequest searchScrollRequest = new SearchScrollRequest(scrollState.getScrollId())
 									.scroll(scrollTimeout);
-							request.emitNext(searchScrollRequest);
+							tryEmitNext(requests, searchScrollRequest);
 						}
 
 					}).map(SearchResponse::getHits) //
@@ -513,7 +514,7 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 
 					return searchHits.doOnSubscribe(ignore -> {
 						exchange.subscribe(inbound);
-						request.emitNext(searchRequest);
+						tryEmitNext(requests, searchRequest);
 					});
 
 				}, state -> cleanupScroll(headers, state), //
@@ -521,6 +522,15 @@ public class DefaultReactiveElasticsearchClient implements ReactiveElasticsearch
 				state -> cleanupScroll(headers, state)); //
 	}
 
+	private void tryEmitNext(Sinks.Many<ActionRequest> sink, ActionRequest request) {
+
+		Sinks.Emission emission = sink.tryEmitNext(request);
+
+		if (emission == Sinks.Emission.FAIL_OVERFLOW) {
+			sink.tryEmitError(Exceptions.failWithOverflow("Backpressure overflow during Sinks.Many#emitNext"));
+		}
+	}
+
 	private static boolean isEmpty(@Nullable SearchHits hits) {
 		return hits != null && hits.getHits() != null && hits.getHits().length == 0;
 	}