diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
index 6491013f5a84..8c3ae87ef01a 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache
@@ -512,6 +512,15 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
         return mediaType != null && (MediaType.APPLICATION_JSON.isCompatibleWith(mediaType) || mediaType.getSubtype().matches("^.*\\+json[;]?\\s*$"));
     }
 
+    /**
+    * Check if the given {@code String} is a Problem JSON MIME (RFC-7807).
+    * @param mediaType the input MediaType
+    * @return boolean true if the MediaType represents Problem JSON, false otherwise
+    */
+    public boolean isProblemJsonMime(String mediaType) {
+        return "application/problem+json".equalsIgnoreCase(mediaType);
+    }
+
     /**
      * Select the Accept header's value from the given accepts array:
      *     if JSON exists in the given array, use it;
@@ -526,7 +535,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
         }
         for (String accept : accepts) {
             MediaType mediaType = MediaType.parseMediaType(accept);
-            if (isJsonMime(mediaType)) {
+            if (isJsonMime(mediaType) && !isProblemJsonMime(accept)) {
                 return Collections.singletonList(mediaType);
             }
         }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
index b8a53e2f9470..a5823b9bbb3d 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java
@@ -497,6 +497,15 @@ public boolean isJsonMime(MediaType mediaType) {
         return mediaType != null && (MediaType.APPLICATION_JSON.isCompatibleWith(mediaType) || mediaType.getSubtype().matches("^.*\\+json[;]?\\s*$"));
     }
 
+    /**
+    * Check if the given {@code String} is a Problem JSON MIME (RFC-7807).
+    * @param mediaType the input MediaType
+    * @return boolean true if the MediaType represents Problem JSON, false otherwise
+    */
+    public boolean isProblemJsonMime(String mediaType) {
+        return "application/problem+json".equalsIgnoreCase(mediaType);
+    }
+
     /**
      * Select the Accept header's value from the given accepts array:
      *     if JSON exists in the given array, use it;
@@ -511,7 +520,7 @@ public List<MediaType> selectHeaderAccept(String[] accepts) {
         }
         for (String accept : accepts) {
             MediaType mediaType = MediaType.parseMediaType(accept);
-            if (isJsonMime(mediaType)) {
+            if (isJsonMime(mediaType) && !isProblemJsonMime(accept)) {
                 return Collections.singletonList(mediaType);
             }
         }