diff --git a/go.mod b/go.mod
index 28956b72..36f8fa89 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,12 @@ module github.com/sigstore/protobuf-specs
 
 go 1.18
 
-require google.golang.org/protobuf v1.28.1
+require (
+	google.golang.org/genproto/googleapis/api v0.0.0-20230726155614-23370e0ffb3e
+	google.golang.org/protobuf v1.31.0
+)
 
-require github.com/google/go-cmp v0.5.8 // indirect
+require (
+	github.com/google/go-cmp v0.5.8 // indirect
+	google.golang.org/genproto v0.0.0-20230706204954-ccb25ca9f130 // indirect
+)
diff --git a/go.sum b/go.sum
index 1e62e8f0..d2aa6988 100644
--- a/go.sum
+++ b/go.sum
@@ -3,6 +3,10 @@ github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/genproto v0.0.0-20230706204954-ccb25ca9f130 h1:Au6te5hbKUV8pIYWHqOUZ1pva5qK/rwbIhoXEUB9Lu8=
+google.golang.org/genproto v0.0.0-20230706204954-ccb25ca9f130/go.mod h1:O9kGHb51iE/nOGvQaDUuadVYqovW56s5emA88lQnj6Y=
+google.golang.org/genproto/googleapis/api v0.0.0-20230726155614-23370e0ffb3e h1:z3vDksarJxsAKM5dmEGv0GHwE2hKJ096wZra71Vs4sw=
+google.golang.org/genproto/googleapis/api v0.0.0-20230726155614-23370e0ffb3e/go.mod h1:rsr7RhLuwsDKL7RmgDDCUc6yaGr1iqceVb5Wv6f6YvQ=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
-google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=