diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..e2b022b
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,9 @@
+# v0.5.1 - September 11, 2015
+
+- Add this `CHANGLEOG`.
+- Fix issue [#1](https://github.com/jessedoyle/duktape.cr/issues/1) by linking against standard math library.
+- Cleanup `Makefile` syntax.
+
+# v0.5.0 - September 8, 2015
+
+- Intial public release.
\ No newline at end of file
diff --git a/README.md b/README.md
index f489a48..6ec61c7 100644
--- a/README.md
+++ b/README.md
@@ -84,7 +84,7 @@ sbx.get_prop -2          # [ global Math ]
 sbx.push_string "PI"     # [ global Math "PI" ]
 sbx.get_prop -2          # [ global Math PI ]
 pi = sbx.get_number -1
-puts "PI: #{pi}"
+puts "PI: #{pi}"         # => PI: 3.14159
 sbx.pop_3
 ```
 
@@ -116,7 +116,7 @@ will raise `Duktape::Error "SyntaxError"`.
 
 ## Sandbox vs Context
 
-You should only execute untrusted javascript code on from within a `Duktape::Sandbox` instance. A sandbox isolates code from insecure operations such as Duktape's internal `require` mechanism and the `Duktape` global javascript object.
+You should only execute untrusted javascript code from within a `Duktape::Sandbox` instance. A sandbox isolates code from insecure operations such as Duktape's internal `require` mechanism and the `Duktape` global javascript object.
 
 Note that a sandbox does not currently protect against infinite loops or excessive runtime. Ideally, a timeout mechanism will be available in future releases.
 
diff --git a/shard.yml b/shard.yml
index a8a2469..c39a04c 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,5 +1,5 @@
 name: duktape.cr
-version: 0.5.0
+version: 0.5.1
 
 authors:
   - Jesse Doyle <jdoyle@ualberta.ca>
diff --git a/src/duktape/version.cr b/src/duktape/version.cr
index 750e03d..3d4b684 100644
--- a/src/duktape/version.cr
+++ b/src/duktape/version.cr
@@ -16,7 +16,7 @@ module Duktape
   module VERSION
     MAJOR = 0
     MINOR = 5
-    TINY  = 0
+    TINY  = 1
     PRE   = nil
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join "."