diff --git a/changelog.org b/changelog.org
index c07a6df..9007da6 100644
--- a/changelog.org
+++ b/changelog.org
@@ -1,3 +1,7 @@
+* v0.4.1
+- fix issue #48 where the unit parsing logic accepted invalid SI
+  prefixes and thus code like ~foo.toMeter~ was valid (and looked like
+  sensible code)
 * v0.4.0
 - add unit of ~Barn~
 - BREAKING: rename short form of Gauss to ~gauss~. Single capital ~G~
diff --git a/unchained.nimble b/unchained.nimble
index 41f273c..2cdc514 100644
--- a/unchained.nimble
+++ b/unchained.nimble
@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.4.0"
+version       = "0.4.1"
 author        = "Vindaar"
 description   = "Fully type safe, compile time only units library"
 license       = "MIT"