diff --git a/README.md b/README.md
index e9582c73a..c384631f5 100644
--- a/README.md
+++ b/README.md
@@ -131,7 +131,7 @@ spec:
   issuerRef:
     name: letsencrypt-staging
   # A list of domains to include on the TLS certificate
-  domains:
+  dnsNames:
   - example.com
   - www.example.com
   - example2.com
diff --git a/docs/examples/acme-cert.yaml b/docs/examples/acme-cert.yaml
index a3af64d7a..02d582ae4 100644
--- a/docs/examples/acme-cert.yaml
+++ b/docs/examples/acme-cert.yaml
@@ -8,7 +8,7 @@ spec:
   secretName: cm-http-nginx-k8s-group
   issuerRef:
     name: letsencrypt-staging
-  domains:
+  dnsNames:
   - cm-http-nginx.k8s.group
   - cm-http-nginx2.k8s.group
   - cm-http-gce.k8s.group
diff --git a/docs/examples/ca-cert.yaml b/docs/examples/ca-cert.yaml
index a6fd9c8a6..e3a0de77b 100644
--- a/docs/examples/ca-cert.yaml
+++ b/docs/examples/ca-cert.yaml
@@ -11,5 +11,5 @@ spec:
     # We can reference ClusterIssuers by changing the kind here.
     # The default value is Issuer (i.e. a locally namespaced Issuer)
     kind: Issuer
-  domains:
+  dnsNames:
   - cert-manager.k8s.io
diff --git a/pkg/apis/certmanager/v1alpha1/types.go b/pkg/apis/certmanager/v1alpha1/types.go
index c1f02aa9e..f776e1eb9 100644
--- a/pkg/apis/certmanager/v1alpha1/types.go
+++ b/pkg/apis/certmanager/v1alpha1/types.go
@@ -224,8 +224,8 @@ type CertificateList struct {
 type CertificateSpec struct {
 	// CommonName is a common name to be used on the Certificate
 	CommonName string `json:"commonName"`
-	// AltNames is a list of subject alt names to be used on the Certificate
-	AltNames []string `json:"altNames"`
+	// DNSNames is a list of subject alt names to be used on the Certificate
+	DNSNames []string `json:"dnsNames"`
 	// SecretName is the name of the secret resource to store this secret in
 	SecretName string `json:"secretName"`
 	// IssuerRef is a reference to the issuer for this certificate. If the