diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
index fb80f0d2dba..3bcf3ede667 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
@@ -18,6 +18,7 @@ import io.vertx.core.file.FileSystem;
 import io.vertx.core.file.OpenOptions;
 import io.vertx.core.http.HttpHeaders;
 import io.vertx.core.http.HttpMethod;
+import io.vertx.core.json.DecodeException;
 import io.vertx.core.json.Json;
 import io.vertx.core.json.JsonObject;
 import io.vertx.ext.web.client.HttpRequest;
@@ -553,7 +554,11 @@ public class ApiClient {
                             handleFileDownload(httpResponse, handler);
                             return;
                         } else {
-                            resultContent = Json.decodeValue(httpResponse.body(), returnType);
+                            try {
+                                resultContent = Json.mapper.readValue(httpResponse.bodyAsString(), returnType);
+                            } catch (Exception e) {
+                                throw new DecodeException("Failed to decode:" + e.getMessage(), e);
+                            }
                         }
                         result = Future.succeededFuture(resultContent);
                     }
@@ -597,4 +602,4 @@ public class ApiClient {
             auth.applyToParams(queryParams, headerParams);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/ApiClient.java
index 49e53810020..b77033426da 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/ApiClient.java
@@ -18,6 +18,7 @@ import io.vertx.core.file.FileSystem;
 import io.vertx.core.file.OpenOptions;
 import io.vertx.core.http.HttpHeaders;
 import io.vertx.core.http.HttpMethod;
+import io.vertx.core.json.DecodeException;
 import io.vertx.core.json.Json;
 import io.vertx.core.json.JsonObject;
 import io.vertx.ext.web.client.HttpRequest;
@@ -554,7 +555,11 @@ public class ApiClient {
                             handleFileDownload(httpResponse, handler);
                             return;
                         } else {
-                            resultContent = Json.decodeValue(httpResponse.body(), returnType);
+                            try {
+                                resultContent = Json.mapper.readValue(httpResponse.bodyAsString(), returnType);
+                            } catch (Exception e) {
+                                throw new DecodeException("Failed to decode:" + e.getMessage(), e);
+                            }
                         }
                         result = Future.succeededFuture(resultContent);
                     }
@@ -598,4 +603,4 @@ public class ApiClient {
             auth.applyToParams(queryParams, headerParams);
         }
     }
-}
\ No newline at end of file
+}