diff --git a/common/certificate_type.h b/common/certificate_type.h
new file mode 100644
index 0000000..1d07166
--- /dev/null
+++ b/common/certificate_type.h
@@ -0,0 +1,16 @@
+// Copyright 2017 Google LLC. All rights reserved.
+
+#ifndef VIDEO_WIDEVINE_EXPORT_COMMON_CERTIFICATE_TYPE_H_
+#define VIDEO_WIDEVINE_EXPORT_COMMON_CERTIFICATE_TYPE_H_
+
+namespace video_widevine {
+
+enum CertificateType {
+  kCertificateTypeTesting,
+  kCertificateTypeDevelopment,
+  kCertificateTypeProduction,
+};
+
+}  // namespace video_widevine
+
+#endif  // VIDEO_WIDEVINE_EXPORT_COMMON_CERTIFICATE_TYPE_H_