diff --git a/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java b/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
index 8e420b57fc..d273e58373 100644
--- a/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
+++ b/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
@@ -140,6 +140,7 @@ public void setFormat(String format) {
     }
 
     public void addRequired(String name) {
+        this.required.add(name);
         Property p = properties.get(name);
         if (p != null) {
             p.setRequired(true);
@@ -166,8 +167,8 @@ public List<String> getRequired() {
 
     public void setRequired(List<String> required) {
         this.required = required;
-        for (String s : required) {
-            if (properties != null) {
+        if (properties != null){
+            for (String s : required) {
                 Property p = properties.get(s);
                 if (p != null) {
                     p.setRequired(true);
@@ -370,4 +371,4 @@ public boolean equals(Object obj) {
         }
         return true;
     }
-}
\ No newline at end of file
+}