diff --git a/Documentation/app-container.md b/Documentation/app-container.md
index 371a1f5..97643ee 100644
--- a/Documentation/app-container.md
+++ b/Documentation/app-container.md
@@ -12,8 +12,8 @@ To validate that `rkt` successfully implements the ACE part of the spec, use the
 
 ```
 $ sudo rkt --insecure-skip-verify run --volume database,kind=host,source=/tmp
-	https://github.com/appc/spec/releases/download/v0.4.1/ace-validator-main.aci
-	https://github.com/appc/spec/releases/download/v0.4.1/ace-validator-sidekick.aci
+	https://github.com/appc/spec/releases/download/v0.5.1/ace-validator-main.aci
+	https://github.com/appc/spec/releases/download/v0.5.1/ace-validator-sidekick.aci
 ```
 
 [appc-repo]: https://github.com/appc/spec/
diff --git a/README.md b/README.md
index 4f3c504..196afd6 100644
--- a/README.md
+++ b/README.md
@@ -18,9 +18,9 @@ The CLI for Rocket is called `rkt`, and is currently supported on amd64 Linux. A
 To install the `rkt` binary, grab the latest release directly from GitHub:
 
 ```
-wget https://github.com/coreos/rocket/releases/download/v0.4.2/rocket-v0.4.2.tar.gz
-tar xzvf rocket-v0.4.2.tar.gz
-cd rocket-v0.4.2
+wget https://github.com/coreos/rocket/releases/download/v0.5.1/rocket-v0.5.1.tar.gz
+tar xzvf rocket-v0.5.1.tar.gz
+cd rocket-v0.5.1
 ./rkt help
 ```
 
diff --git a/cas/cas_test.go b/cas/cas_test.go
index 7f0b29b..986d978 100644
--- a/cas/cas_test.go
+++ b/cas/cas_test.go
@@ -155,7 +155,7 @@ func TestGetImageManifest(t *testing.T) {
 
 	imj := `{
 			"acKind": "ImageManifest",
-			"acVersion": "0.4.0",
+			"acVersion": "0.5.1",
 			"name": "example.com/test01"
 		}`
 
@@ -347,7 +347,7 @@ func TestTreeStore(t *testing.T) {
 	imj := `
 		{
 		    "acKind": "ImageManifest",
-		    "acVersion": "0.4.1",
+		    "acVersion": "0.5.1",
 		    "name": "example.com/test01"
 		}
 	`
diff --git a/cas/tree_test.go b/cas/tree_test.go
index 3667257..3de9139 100644
--- a/cas/tree_test.go
+++ b/cas/tree_test.go
@@ -13,7 +13,7 @@ func treeStoreDSWriteACI(dir string, ds *Store) (string, error) {
 	imj := `
 		{
 		    "acKind": "ImageManifest",
-		    "acVersion": "0.4.1",
+		    "acVersion": "0.5.1",
 		    "name": "example.com/test01"
 		}
 	`
diff --git a/pkg/aci/aci.go b/pkg/aci/aci.go
index e6ccddd..6d4b767 100644
--- a/pkg/aci/aci.go
+++ b/pkg/aci/aci.go
@@ -106,7 +106,7 @@ func (aw *imageArchiveWriter) Close() error {
 // NewBasicACI creates a new ACI in the given directory with the given name.
 // Used for testing.
 func NewBasicACI(dir string, name string) (*os.File, error) {
-	manifest := fmt.Sprintf(`{"acKind":"ImageManifest","acVersion":"0.4.1","name":"%s"}`, name)
+	manifest := fmt.Sprintf(`{"acKind":"ImageManifest","acVersion":"0.5.1","name":"%s"}`, name)
 	return NewACI(dir, manifest, nil)
 }
 
diff --git a/rkt/fetch_test.go b/rkt/fetch_test.go
index f41af09..744865c 100644
--- a/rkt/fetch_test.go
+++ b/rkt/fetch_test.go
@@ -124,7 +124,7 @@ func TestDownloading(t *testing.T) {
 
 	imj := `{
 			"acKind": "ImageManifest",
-			"acVersion": "0.4.0",
+			"acVersion": "0.5.1",
 			"name": "example.com/test01"
 		}`
 
diff --git a/version/version.go b/version/version.go
index 5cf8c0d..8bbd676 100644
--- a/version/version.go
+++ b/version/version.go
@@ -14,4 +14,4 @@
 
 package version
 
-const Version = "0.4.2+git"
+const Version = "0.5.1"