diff --git a/docs/resources/resource.md b/docs/resources/resource.md
index e44ca1e..aa6b33a 100644
--- a/docs/resources/resource.md
+++ b/docs/resources/resource.md
@@ -18,9 +18,12 @@ Sample resource in the Terraform provider containerregistry.
 ### Required
 
 - `image_tarball` (String) Image tarball thing.
-- `image_tarball_hash` (String) Hash of the image tarball.
 - `remote_tag` (String) The tag to save the image to.
 
+### Optional
+
+- `image_tarball_hash` (String) Hash of the image tarball.
+
 ### Read-Only
 
 - `id` (String) The ID of this resource.
diff --git a/provider/resource_containerregistry.go b/provider/resource_containerregistry.go
index 4fe80bd..5c89860 100644
--- a/provider/resource_containerregistry.go
+++ b/provider/resource_containerregistry.go
@@ -34,7 +34,8 @@ func resourceContainerregistry() *schema.Resource {
 				// This description is used by the documentation generator and the language server.
 				Description: "Hash of the image tarball.",
 				Type:        schema.TypeString,
-				Required:    true,
+				Required:    false,
+				Optional:    true,
 				ForceNew:    true,
 			},
 			"remote_tag": {