diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0d2931..a98d3fb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [0.3.1] - 2017-08-18
+
+ * New option flag: `--strict` that will instruct the parser to reject plans
+   with undefined projects (_i.e._ used in expressions but never defined).
+ * Fix: make cost and trust value rendering consistent for leaf and non-leaf
+   projects - now they are partial everywhere.
+
 ## [0.3.0] - 2017-08-17
 
 New option flag: `--render-parse-error` which will render the image with the
diff --git a/README.md b/README.md
index c9a2836..7402732 100644
--- a/README.md
+++ b/README.md
@@ -48,9 +48,9 @@ planning progress can be recorded.
 ```
 master-plan - project management tool for hackers
 
-Usage: master-plan [FILENAME] [-o|--output FILENAME] [--progress-below N]
-                   [--render-parse-error] [-c|--color] [-w|--width NUMBER]
-                   [--height NUMBER] [-r|--root NAME]
+Usage: master-plan [FILENAME] [-o|--output FILENAME] [-r|--root NAME]
+                   [--progress-below N] [--render-parse-error] [--strict]
+                   [-c|--color] [-w|--width NUMBER] [--height NUMBER]
                    [--hide title|description|url|owner|cost|trust|progress]
   See documentation on how to write project plan files
 
@@ -58,13 +58,14 @@ Available options:
   FILENAME                 plan file to read from (default from stdin)
   -o,--output FILENAME     output file name (.png, .tif, .bmp, .jpg and .pdf
                            supported)
+  -r,--root NAME           name of the root project definition (default: "root")
   --progress-below N       only display projects which progress is < N%
   --render-parse-error     instead of printing parsing errors, render as an
                            image
+  --strict                 strict parsing: every project has to be defined
   -c,--color               color each project by progress
   -w,--width NUMBER        width of the output image
   --height NUMBER          height of the output image
-  -r,--root NAME           name of the root project definition (default: "root")
   --hide title|description|url|owner|cost|trust|progress
                            hide a particular property
   -h,--help                Show this help text
diff --git a/master-plan.cabal b/master-plan.cabal
index af2c187..9fbaeee 100644
--- a/master-plan.cabal
+++ b/master-plan.cabal
@@ -1,5 +1,5 @@
 name:                master-plan
-version:             0.3.0
+version:             0.3.1
 synopsis:            The project management tool for hackers
 description:         Master Plan is a tool that parses files that describes
                      projects using a simple and powerful syntax in which