diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
index daa0551e31d..92f1a483c0f 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
@@ -2578,7 +2578,9 @@ public CodegenParameter fromParameter(Parameter param, Set<String> imports) {
                 // recursively add import
                 CodegenProperty innerCp = cp;
                 while(innerCp != null) {
-                    imports.add(innerCp.complexType);
+                    if(innerCp.complexType != null) {
+                        imports.add(innerCp.complexType);
+                    }
                     innerCp = innerCp.items;
                 }