diff --git a/signature/policy_types.go b/signature/policy_types.go
index 32aa1c0ad4..ccc1a38d9a 100644
--- a/signature/policy_types.go
+++ b/signature/policy_types.go
@@ -120,7 +120,7 @@ type prSigstoreSigned struct {
 	// KeyDatas is a set of trusted keys, base64-encoded. Exactly one of KeyPath, KeyPaths, KeyData, KeyDatas and Fulcio must be specified.
 	KeyDatas [][]byte `json:"keyDatas,omitempty"`
 
-	// Fulcio specifies which Fulcio-generated certificates are accepted. Exactly one of KeyPath, KeyPaths, KeyData, KeyDatas and Fulcio must be specified.
+	// Fulcio specifies which Fulcio-generated certificates are accepted. Exactly one of KeyPath, KeyPaths, KeyData, KeyDatas, Fulcio, and PKI must be specified.
 	// If Fulcio is specified, one of RekorPublicKeyPath or RekorPublicKeyData must be specified as well.
 	Fulcio PRSigstoreSignedFulcio `json:"fulcio,omitempty"`
 
@@ -141,6 +141,9 @@ type prSigstoreSigned struct {
 	// otherwise it is optional (and Rekor inclusion is not required if a Rekor public key is not specified).
 	RekorPublicKeyDatas [][]byte `json:"rekorPublicKeyDatas,omitempty"`
 
+	// PKI specifies which PKI-generated certificates are accepted. Exactly one of KeyPath, KeyData, Fulcio, PKI must be specified.
+	PKI prSigstoreSignedPKI `json:"pki,omitempty"`
+
 	// SignedIdentity specifies what image identity the signature must be claiming about the image.
 	// Defaults to "matchRepoDigestOrExact" if not specified.
 	// Note that /usr/bin/cosign interoperability might require using repo-only matching.
@@ -167,6 +170,22 @@ type prSigstoreSignedFulcio struct {
 	SubjectEmail string `json:"subjectEmail,omitempty"`
 }
 
+// prSigstoreSignedPKI contains non-fulcio certificate PKI configuration options for prSigstoreSigned
+type prSigstoreSignedPKI struct {
+	// CARootsPath a path to a file containing accepted CA root certificates, in PEM format. Exactly one of CARootsPath and CARootsData must be specified.
+	CARootsPath string `json:"caRootsPath"`
+	// CARootsData contains accepted CA root certificates in PEM format, all of that base64-encoded. Exactly one of CARootsPath and CARootsData must be specified.
+	CARootsData []byte `json:"caRootsData"`
+	// CAIntermediatesPath a path to a file containing accepted CA intermediate certificates, in PEM format. Only one of CAIntermediatesPath or CAIntermediatesData can be specified, not both.
+	CAIntermediatesPath string `json:"caIntermediatesPath"`
+	// CAIntermediatesData contains accepted CA intermediate certificates in PEM format, all of that base64-encoded. Only one of CAIntermediatesPath or CAIntermediatesData can be specified, not both.
+	CAIntermediatesData []byte `json:"caIntermediatesData"`
+	// SubjectEmail specifies the expected email address imposed on the subject to which the certificate was issued. Exactly one of SubjectEmail and Hostname must be specified.
+	SubjectEmail string `json:"subjectEmail"`
+	// Hostname specifies the expected hostname imposed on the subject to which the certificate was issued. Exactly one of SubjectEmail and Hostname must be specified.
+	Hostname string `json:"hostname"`
+}
+
 // PolicyReferenceMatch specifies a set of image identities accepted in PolicyRequirement.
 // The type is public, but its implementation is private.