diff --git a/Dockerfile b/Dockerfile
index 4acfdd4..ac2e6d3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -44,6 +44,8 @@ RUN npm install -g geojsontoosm
 RUN npm install -g geojson2poly 
 RUN npm install -g geojson-pick
 RUN npm install -g @mapbox/geojson-merge
+# https://github.com/tmcw/geojson-flatten
+RUN npm install -g geojson-flatten
 
 # Install osmconvert and osmfilter
 RUN wget -O - http://m.m.i24.cc/osmconvert.c | cc -x c - -lz -O3 -o osmconvert
diff --git a/README.MD b/README.MD
index 0198f1c..78a9449 100644
--- a/README.MD
+++ b/README.MD
@@ -370,3 +370,13 @@ geojson-pick PROPERTYNAME1 < input.geojson > output.geojson
 ```
 geokit dosm -d ayac.geojson --api=overpass --zoom=16
 ```
+
+
+### [geojson-flatten](https://github.com/tmcw/geojson-flatten)
+
+- Flatten multi geometries into normal geometries
+
+
+```
+geojson-flatten input.geojson > flattened.geojson
+```
\ No newline at end of file