diff --git a/api/v1alpha1/gitrepository_types.go b/api/v1alpha1/gitrepository_types.go
index 7636df0f9..a6c82a26d 100644
--- a/api/v1alpha1/gitrepository_types.go
+++ b/api/v1alpha1/gitrepository_types.go
@@ -42,8 +42,7 @@ type GitRepositorySpec struct {
 	// +required
 	Interval metav1.Duration `json:"interval"`
 
-	// The timeout for remote git operations like cloning.
-	// +kubebuilder:validation:Default=20s
+	// The timeout for remote git operations like cloning, default to 20s.
 	// +optional
 	Timeout *metav1.Duration `json:"timeout,omitempty"`
 
@@ -61,20 +60,19 @@ type GitRepositorySpec struct {
 type GitRepositoryRef struct {
 	// The git branch to checkout, defaults to master.
 	// +optional
-	Branch string `json:"branch"`
+	Branch string `json:"branch,omitempty"`
 
 	// The git tag to checkout, takes precedence over branch.
 	// +optional
-	Tag string `json:"tag"`
+	Tag string `json:"tag,omitempty"`
 
 	// The git tag semver expression, takes precedence over tag.
 	// +optional
-	SemVer string `json:"semver"`
+	SemVer string `json:"semver,omitempty"`
 
-	// The git commit sha to checkout, if specified tag filters will be
-	// ignored.
+	// The git commit sha to checkout, if specified tag filters will be ignored.
 	// +optional
-	Commit string `json:"commit"`
+	Commit string `json:"commit,omitempty"`
 }
 
 // GitRepositoryVerification defines the OpenPGP signature verification process.
diff --git a/config/crd/bases/source.fluxcd.io_gitrepositories.yaml b/config/crd/bases/source.fluxcd.io_gitrepositories.yaml
index 3b1ac754b..049544737 100644
--- a/config/crd/bases/source.fluxcd.io_gitrepositories.yaml
+++ b/config/crd/bases/source.fluxcd.io_gitrepositories.yaml
@@ -83,7 +83,8 @@ spec:
                   type: string
               type: object
             timeout:
-              description: The timeout for remote git operations like cloning.
+              description: The timeout for remote git operations like cloning, default
+                to 20s.
               type: string
             url:
               description: The repository URL, can be a HTTP or SSH address.
diff --git a/docs/spec/v1alpha1/gitrepositories.md b/docs/spec/v1alpha1/gitrepositories.md
index bfef59223..3db341ce0 100644
--- a/docs/spec/v1alpha1/gitrepositories.md
+++ b/docs/spec/v1alpha1/gitrepositories.md
@@ -27,8 +27,7 @@ type GitRepositorySpec struct {
 	// The interval at which to check for repository updates.
 	Interval metav1.Duration `json:"interval"`
 
-	// The timeout for remote git operations like cloning.
-	// +kubebuilder:validation:Default=20s
+	// The timeout for remote git operations like cloning, default to 20s.
 	// +optional
 	Timeout *metav1.Duration `json:"timeout,omitempty"`
 
@@ -50,20 +49,19 @@ Git repository reference:
 type GitRepositoryRef struct {
 	// The git branch to checkout, defaults to master.
 	// +optional
-	Branch string `json:"branch"`
+	Branch string `json:"branch,omitempty"`
 
 	// The git tag to checkout, takes precedence over branch.
 	// +optional
-	Tag string `json:"tag"`
+	Tag string `json:"tag,omitempty"`
 
 	// The git tag semver expression, takes precedence over tag.
 	// +optional
-	SemVer string `json:"semver"`
+	SemVer string `json:"semver,omitempty"`
 
-	// The git commit sha to checkout, if specified branch and tag filters will
-	// ignored.
+	// The git commit sha to checkout, if specified tag filters will be ignored.
 	// +optional
-	Commit string `json:"commit"`
+	Commit string `json:"commit,omitempty"`
 }
 ```