diff --git a/api/v1alpha1/artifact.go b/api/v1alpha1/artifact.go
index ff3e59ff..b9bac76b 100644
--- a/api/v1alpha1/artifact.go
+++ b/api/v1alpha1/artifact.go
@@ -23,9 +23,9 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
-// Artifact represents the output of a source synchronisation
+// Artifact represents the output of a source synchronisation.
 type Artifact struct {
-	// Path is the local file path of this artifact.
+	// Path is the relative file path of this artifact.
 	// +required
 	Path string `json:"path"`
 
@@ -33,12 +33,16 @@ type Artifact struct {
 	// +required
 	URL string `json:"url"`
 
-	// Revision is a human readable identifier traceable in the origin source system.
-	// It can be a commit sha, git tag, a helm index timestamp,
-	// a helm chart version, a checksum, etc.
+	// Revision is a human readable identifier traceable in the origin
+	// source system. It can be a Git commit sha, Git tag, a Helm index
+	// timestamp, a Helm chart version, etc.
 	// +optional
 	Revision string `json:"revision"`
 
+	// Checksum is the SHA1 checksum of the artifact.
+	// +optional
+	Checksum string `json:"checksum"`
+
 	// LastUpdateTime is the timestamp corresponding to the last
 	// update of this artifact.
 	// +required
@@ -46,14 +50,14 @@ type Artifact struct {
 }
 
 // ArtifactDir returns the artifact dir path in the form of
-// <source-kind>/<source-namespace>/<source-name>
+// <source-kind>/<source-namespace>/<source-name>.
 func ArtifactDir(kind, namespace, name string) string {
 	kind = strings.ToLower(kind)
 	return path.Join(kind, namespace, name)
 }
 
 // ArtifactPath returns the artifact path in the form of
-// <source-kind>/<source-namespace>/<source-name>/<artifact-filename>
+// <source-kind>/<source-namespace>/<source-name>/<artifact-filename>.
 func ArtifactPath(kind, namespace, name, filename string) string {
 	return path.Join(ArtifactDir(kind, namespace, name), filename)
 }
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml b/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
index 2a339ee9..e60d5852 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_gitrepositories.yaml
@@ -129,18 +129,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   repository sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      in the origin source system. It can be a Git commit sha, Git
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml b/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
index e66ef34d..d1125575 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_helmcharts.yaml
@@ -101,18 +101,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   chart sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      in the origin source system. It can be a Git commit sha, Git
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.
diff --git a/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml b/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
index e165ee19..8f7f675e 100644
--- a/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
+++ b/config/crd/bases/source.toolkit.fluxcd.io_helmrepositories.yaml
@@ -81,18 +81,21 @@ spec:
                 description: Artifact represents the output of the last successful
                   repository sync.
                 properties:
+                  checksum:
+                    description: Checksum is the SHA1 checksum of the artifact.
+                    type: string
                   lastUpdateTime:
                     description: LastUpdateTime is the timestamp corresponding to
                       the last update of this artifact.
                     format: date-time
                     type: string
                   path:
-                    description: Path is the local file path of this artifact.
+                    description: Path is the relative file path of this artifact.
                     type: string
                   revision:
                     description: Revision is a human readable identifier traceable
-                      in the origin source system. It can be a commit sha, git tag,
-                      a helm index timestamp, a helm chart version, a checksum, etc.
+                      in the origin source system. It can be a Git commit sha, Git
+                      tag, a Helm index timestamp, a Helm chart version, etc.
                     type: string
                   url:
                     description: URL is the HTTP address of this artifact.
diff --git a/controllers/gitrepository_controller.go b/controllers/gitrepository_controller.go
index b1aa96fc..eed5478f 100644
--- a/controllers/gitrepository_controller.go
+++ b/controllers/gitrepository_controller.go
@@ -212,8 +212,10 @@ func (r *GitRepositoryReconciler) reconcile(ctx context.Context, repository sour
 		}
 	}
 
+	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
+	//   has been merged.
 	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s.tar.gz", commit.Hash.String()), revision)
+		fmt.Sprintf("%s.tar.gz", commit.Hash.String()), revision, "")
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
diff --git a/controllers/helmchart_controller.go b/controllers/helmchart_controller.go
index 8c02c2f1..58f07c4b 100644
--- a/controllers/helmchart_controller.go
+++ b/controllers/helmchart_controller.go
@@ -261,7 +261,7 @@ func (r *HelmChartReconciler) reconcileFromHelmRepository(ctx context.Context,
 
 	sum := r.Storage.Checksum(chartBytes)
 	artifact := r.Storage.ArtifactFor(chart.Kind, chart.GetObjectMeta(),
-		fmt.Sprintf("%s-%s-%s.tgz", cv.Name, cv.Version, sum), cv.Version)
+		fmt.Sprintf("%s-%s-%s.tgz", cv.Name, cv.Version, sum), cv.Version, sum)
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
@@ -365,8 +365,10 @@ func (r *HelmChartReconciler) reconcileFromGitRepository(ctx context.Context,
 		return chart, nil
 	}
 
+	// TODO(hidde): implement checksum when https://github.com/fluxcd/source-controller/pull/133
+	//   has been merged.
 	artifact := r.Storage.ArtifactFor(chart.Kind, chart.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version), chartMetadata.Version)
+		fmt.Sprintf("%s-%s.tgz", chartMetadata.Name, chartMetadata.Version), chartMetadata.Version, "")
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
diff --git a/controllers/helmrepository_controller.go b/controllers/helmrepository_controller.go
index 1bd37268..feb28b76 100644
--- a/controllers/helmrepository_controller.go
+++ b/controllers/helmrepository_controller.go
@@ -229,7 +229,7 @@ func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, repository sou
 
 	sum := r.Storage.Checksum(index)
 	artifact := r.Storage.ArtifactFor(repository.Kind, repository.ObjectMeta.GetObjectMeta(),
-		fmt.Sprintf("index-%s.yaml", sum), sum)
+		fmt.Sprintf("index-%s.yaml", sum), i.Generated.Format(time.RFC3339Nano), sum)
 
 	// create artifact dir
 	err = r.Storage.MkdirAll(artifact)
diff --git a/controllers/storage.go b/controllers/storage.go
index 9bb7814a..6df68106 100644
--- a/controllers/storage.go
+++ b/controllers/storage.go
@@ -70,7 +70,7 @@ func NewStorage(basePath string, hostname string, timeout time.Duration) (*Stora
 }
 
 // ArtifactFor returns an artifact for the v1alpha1.Source.
-func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, revision string) sourcev1.Artifact {
+func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, revision, checksum string) sourcev1.Artifact {
 	path := sourcev1.ArtifactPath(kind, metadata.GetNamespace(), metadata.GetName(), fileName)
 	localPath := filepath.Join(s.BasePath, path)
 	url := fmt.Sprintf("http://%s/%s", s.Hostname, path)
@@ -79,6 +79,7 @@ func (s *Storage) ArtifactFor(kind string, metadata metav1.Object, fileName, rev
 		Path:           localPath,
 		URL:            url,
 		Revision:       revision,
+		Checksum:       checksum,
 		LastUpdateTime: metav1.Now(),
 	}
 }
diff --git a/docs/api/source.md b/docs/api/source.md
index b32eea5f..b7294757 100644
--- a/docs/api/source.md
+++ b/docs/api/source.md
@@ -458,7 +458,7 @@ HelmRepositoryStatus
 <a href="#source.toolkit.fluxcd.io/v1alpha1.HelmChartStatus">HelmChartStatus</a>, 
 <a href="#source.toolkit.fluxcd.io/v1alpha1.HelmRepositoryStatus">HelmRepositoryStatus</a>)
 </p>
-<p>Artifact represents the output of a source synchronisation</p>
+<p>Artifact represents the output of a source synchronisation.</p>
 <div class="md-typeset__scrollwrap">
 <div class="md-typeset__table">
 <table>
@@ -477,7 +477,7 @@ string
 </em>
 </td>
 <td>
-<p>Path is the local file path of this artifact.</p>
+<p>Path is the relative file path of this artifact.</p>
 </td>
 </tr>
 <tr>
@@ -500,9 +500,21 @@ string
 </td>
 <td>
 <em>(Optional)</em>
-<p>Revision is a human readable identifier traceable in the origin source system.
-It can be a commit sha, git tag, a helm index timestamp,
-a helm chart version, a checksum, etc.</p>
+<p>Revision is a human readable identifier traceable in the origin
+source system. It can be a Git commit sha, Git tag, a Helm index
+timestamp, a Helm chart version, etc.</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>checksum</code><br>
+<em>
+string
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>Checksum is the SHA1 checksum of the artifact.</p>
 </td>
 </tr>
 <tr>
diff --git a/docs/spec/v1alpha1/common.md b/docs/spec/v1alpha1/common.md
index ae8910d9..1007ef79 100644
--- a/docs/spec/v1alpha1/common.md
+++ b/docs/spec/v1alpha1/common.md
@@ -54,9 +54,9 @@ kubectl annotate --overwrite gitrepository/podinfo fluxcd.io/reconcileAt="$(date
 Source objects should contain a status sub-resource that embeds an artifact object:
 
 ```go
-// Artifact represents the output of a source synchronisation
+// Artifact represents the output of a source synchronisation.
 type Artifact struct {
-	// Path is the local file path of this artifact.
+	// Path is the relative file path of this artifact.
 	// +required
 	Path string `json:"path"`
 
@@ -64,12 +64,16 @@ type Artifact struct {
 	// +required
 	URL string `json:"url"`
 
-	// Revision is a human readable identifier traceable in the origin source system.
-	// It can be a commit sha, git tag, a helm index timestamp,
-	// a helm chart version, a checksum, etc.
+	// Revision is a human readable identifier traceable in the origin
+	// source system. It can be a Git commit sha, Git tag, a Helm index
+	// timestamp, a Helm chart version, etc.
 	// +optional
 	Revision string `json:"revision"`
 
+	// Checksum is the SHA1 checksum of the artifact.
+	// +optional
+	Checksum string `json:"checksum"`
+
 	// LastUpdateTime is the timestamp corresponding to the last
 	// update of this artifact.
 	// +required