diff --git a/tools/build/buck-plugin/src/main/java/org/onosproject/onosjar/SwaggerGenerator.java b/tools/build/buck-plugin/src/main/java/org/onosproject/onosjar/SwaggerGenerator.java
index 898be8c..14d401b 100644
--- a/tools/build/buck-plugin/src/main/java/org/onosproject/onosjar/SwaggerGenerator.java
+++ b/tools/build/buck-plugin/src/main/java/org/onosproject/onosjar/SwaggerGenerator.java
@@ -102,10 +102,12 @@
             }
             if (srcs != null) {
                 srcs.forEach(src -> {
-                    try {
-                        builder.addSource(src);
-                    } catch (IOException e) {
-                        throw new RuntimeException(e);
+                    if (src.toString().endsWith(".java")) {
+                        try {
+                            builder.addSource(src);
+                        } catch (IOException e) {
+                            throw new RuntimeException(e);
+                        }
                     }
                 });
             }