diff --git a/components/apimgt/org.wso2.carbon.apimgt.impl/src/main/java/org/wso2/carbon/apimgt/impl/definitions/OASParserUtil.java b/components/apimgt/org.wso2.carbon.apimgt.impl/src/main/java/org/wso2/carbon/apimgt/impl/definitions/OASParserUtil.java
index f828e8db2ab0..4ce783bb67f5 100644
--- a/components/apimgt/org.wso2.carbon.apimgt.impl/src/main/java/org/wso2/carbon/apimgt/impl/definitions/OASParserUtil.java
+++ b/components/apimgt/org.wso2.carbon.apimgt.impl/src/main/java/org/wso2/carbon/apimgt/impl/definitions/OASParserUtil.java
@@ -730,7 +730,9 @@ private static void extractReferenceFromSchema(Schema schema, SwaggerUpdateConte
                 addToReferenceObjectMap(ref, context);
             } else if (!references.isEmpty() && references.size() != 0) {
                 for (String reference : references) {
-                    addToReferenceObjectMap(reference, context);
+                    if (reference != null) {
+                        addToReferenceObjectMap(reference, context);
+                    }
                 }
             }