Update the CHANGELOG and pubspec.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f972461..29f0fbb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.12.2+5
+
+* Remove the dependency on the `collection` package.
+
 ## 0.12.2+4
 
 * Add an example of using command-line arguments to the README.
diff --git a/pubspec.yaml b/pubspec.yaml
index 7ce1981..0af927d 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: args
-version: 0.12.2+5
+version: 0.12.2+6
 author: "Dart Team <misc@dartlang.org>"
 homepage: https://github.com/dart-lang/args
 description: >
@@ -9,4 +9,4 @@
 dev_dependencies:
   unittest: ">=0.11.5 <0.12.0"
 environment:
-  sdk: ">=1.0.0 <2.0.0"
+  sdk: ">=1.4.0 <2.0.0"