diff --git a/README.md b/README.md
index 5b73bfd..c79dc11 100644
--- a/README.md
+++ b/README.md
@@ -24,17 +24,30 @@ Program Usage
 =
 ```
 usage: process_maps.py [-h] [--map-list MAP_LIST] [--no-sleep] [--use-ram]
+                       [--max-heap-space MAX_HEAP_SPACE]
+                       [--output-map-name OUTPUT_MAP_NAME]
+                       [--cached-maps-dir CACHED_MAPS_DIR]
 
 optional arguments:
-  -h, --help           show this help message and exit
-  --map-list MAP_LIST  a text file with one map URL per line, can be specified
-                       more than once
-  --no-sleep           don't sleep between downloads -- WARNING you can easily
-                       run into throttling on mirrors if you use this option
-  --use-ram            use RAM for mapsforge processing -- WARNING mapsforge
-                       uses 10x the map size in RAM for processing (ie. 100Mb
-                       map = 1Gb RAM usage), you want a LOT of RAM for this
-                       option
+  -h, --help            show this help message and exit
+  --map-list MAP_LIST   a text file with one map URL per line, can be
+                        specified more than once
+  --no-sleep            don't sleep between downloads -- WARNING you can
+                        easily run into throttling on mirrors if you use this
+                        option
+  --use-ram             use RAM for mapsforge processing -- WARNING mapsforge
+                        uses 10x the map size in RAM for processing (ie. 100Mb
+                        map = 1Gb RAM usage), you want a LOT of RAM for this
+                        option
+  --max-heap-space MAX_HEAP_SPACE
+                        set the max heap space for the JVM, use standard -Xmx
+                        values, default (4g) should be fine if not using
+                        --use-ram argument
+  --output-map-name OUTPUT_MAP_NAME
+                        set the output .map and .poi file names
+  --cached-maps-dir CACHED_MAPS_DIR
+                        Use cached maps in the specified directory instead of
+                        downloads using map lists
 ```
 
 Licencing