diff --git a/Dockerfile b/Dockerfile
index 5836806..82040aa 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -28,6 +28,6 @@ COPY samba.sh /usr/bin/
 
 VOLUME ["/etc/samba"]
 
-EXPOSE 137 139 445
+EXPOSE 137/udp 138/udp 139 445
 
 ENTRYPOINT ["samba.sh"]
\ No newline at end of file
diff --git a/README.md b/README.md
index 726aa32..d581e7e 100644
--- a/README.md
+++ b/README.md
@@ -64,7 +64,7 @@ ENVIRONMENT VARIABLES (only available with `docker run`)
  * `WORKGROUP` - As above, set workgroup
 
 **NOTE**: if you enable nmbd (via `-n` or the `NMBD` environment variable), you
-will also want to expose port 137 with `-p 137:137`.
+will also want to expose port 137 and 138 with `-p 137:137/udp -p 138:138/udp`.
 
 ## Examples