diff --git a/modules/swagger-codegen/src/main/resources/objc/api-body.mustache b/modules/swagger-codegen/src/main/resources/objc/api-body.mustache
index 53e6895fe33..e4c85166b8b 100644
--- a/modules/swagger-codegen/src/main/resources/objc/api-body.mustache
+++ b/modules/swagger-codegen/src/main/resources/objc/api-body.mustache
@@ -69,6 +69,11 @@ static NSString * basePath = @"{{basePath}}";
         {{#returnBaseType}}{{#hasParams}}completionHandler: {{/hasParams}}(void (^)({{{returnType}}} output, NSError* error))completionBlock{{/returnBaseType}}
         {{^returnBaseType}}{{#hasParams}}completionHandler: {{/hasParams}}(void (^)(NSError* error))completionBlock{{/returnBaseType}} {
 
+    {{#allParams}}{{#required}}
+    // verify the required parameter '{{paramName}}' is set
+    NSAssert({{paramName}} != nil, @"Missing the required parameter `{{paramName}}` when calling {{nickname}}");
+    {{/required}}{{/allParams}}
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@{{path}}", basePath];
 
     // remove format in URL if needed
diff --git a/samples/client/petstore/objc/client/SWGPetApi.m b/samples/client/petstore/objc/client/SWGPetApi.m
index 62bc34acbee..d73018edf97 100644
--- a/samples/client/petstore/objc/client/SWGPetApi.m
+++ b/samples/client/petstore/objc/client/SWGPetApi.m
@@ -67,6 +67,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet", basePath];
 
     // remove format in URL if needed
@@ -158,6 +160,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet", basePath];
 
     // remove format in URL if needed
@@ -249,6 +253,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(NSArray<SWGPet>* output, NSError* error))completionBlock
          {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/findByStatus", basePath];
 
     // remove format in URL if needed
@@ -336,6 +342,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(NSArray<SWGPet>* output, NSError* error))completionBlock
          {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/findByTags", basePath];
 
     // remove format in URL if needed
@@ -423,6 +431,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(SWGPet* output, NSError* error))completionBlock
          {
 
+    
+    // verify the required parameter 'petId' is set
+    NSAssert(petId != nil, @"Missing the required parameter `petId` when calling getPetById");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/{petId}", basePath];
 
     // remove format in URL if needed
@@ -510,6 +523,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'petId' is set
+    NSAssert(petId != nil, @"Missing the required parameter `petId` when calling updatePetWithForm");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/{petId}", basePath];
 
     // remove format in URL if needed
@@ -597,6 +615,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'petId' is set
+    NSAssert(petId != nil, @"Missing the required parameter `petId` when calling deletePet");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/{petId}", basePath];
 
     // remove format in URL if needed
@@ -672,6 +695,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'petId' is set
+    NSAssert(petId != nil, @"Missing the required parameter `petId` when calling uploadFile");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/pet/{petId}/uploadImage", basePath];
 
     // remove format in URL if needed
diff --git a/samples/client/petstore/objc/client/SWGStoreApi.m b/samples/client/petstore/objc/client/SWGStoreApi.m
index c50cf67c5dc..752fc64d601 100644
--- a/samples/client/petstore/objc/client/SWGStoreApi.m
+++ b/samples/client/petstore/objc/client/SWGStoreApi.m
@@ -64,6 +64,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         (void (^)(NSDictionary* output, NSError* error))completionBlock
          {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/store/inventory", basePath];
 
     // remove format in URL if needed
@@ -138,6 +140,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(SWGOrder* output, NSError* error))completionBlock
          {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/store/order", basePath];
 
     // remove format in URL if needed
@@ -243,6 +247,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(SWGOrder* output, NSError* error))completionBlock
          {
 
+    
+    // verify the required parameter 'orderId' is set
+    NSAssert(orderId != nil, @"Missing the required parameter `orderId` when calling getOrderById");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/store/order/{orderId}", basePath];
 
     // remove format in URL if needed
@@ -326,6 +335,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'orderId' is set
+    NSAssert(orderId != nil, @"Missing the required parameter `orderId` when calling deleteOrder");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/store/order/{orderId}", basePath];
 
     // remove format in URL if needed
diff --git a/samples/client/petstore/objc/client/SWGUserApi.m b/samples/client/petstore/objc/client/SWGUserApi.m
index 1316cebd07c..faa086c5d35 100644
--- a/samples/client/petstore/objc/client/SWGUserApi.m
+++ b/samples/client/petstore/objc/client/SWGUserApi.m
@@ -66,6 +66,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user", basePath];
 
     // remove format in URL if needed
@@ -157,6 +159,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/createWithArray", basePath];
 
     // remove format in URL if needed
@@ -248,6 +252,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/createWithList", basePath];
 
     // remove format in URL if needed
@@ -341,6 +347,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(NSString* output, NSError* error))completionBlock
          {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/login", basePath];
 
     // remove format in URL if needed
@@ -427,6 +435,8 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         (void (^)(NSError* error))completionBlock {
 
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/logout", basePath];
 
     // remove format in URL if needed
@@ -495,6 +505,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         completionHandler: (void (^)(SWGUser* output, NSError* error))completionBlock
          {
 
+    
+    // verify the required parameter 'username' is set
+    NSAssert(username != nil, @"Missing the required parameter `username` when calling getUserByName");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/{username}", basePath];
 
     // remove format in URL if needed
@@ -580,6 +595,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'username' is set
+    NSAssert(username != nil, @"Missing the required parameter `username` when calling updateUser");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/{username}", basePath];
 
     // remove format in URL if needed
@@ -672,6 +692,11 @@ static NSString * basePath = @"http://petstore.swagger.io/v2";
         
         completionHandler: (void (^)(NSError* error))completionBlock {
 
+    
+    // verify the required parameter 'username' is set
+    NSAssert(username != nil, @"Missing the required parameter `username` when calling deleteUser");
+    
+
     NSMutableString* requestUrl = [NSMutableString stringWithFormat:@"%@/user/{username}", basePath];
 
     // remove format in URL if needed