diff --git a/packager/hls/base/simple_hls_notifier.cc b/packager/hls/base/simple_hls_notifier.cc
index f016a7a3d5..2ab7087aa5 100644
--- a/packager/hls/base/simple_hls_notifier.cc
+++ b/packager/hls/base/simple_hls_notifier.cc
@@ -58,6 +58,12 @@ bool IsFairPlaySystemId(const std::vector<uint8_t>& system_id) {
                     media::kFairPlaySystemId);
 }
 
+bool IsLegacyFairPlaySystemId(const std::vector<uint8_t>& system_id) {
+  return system_id.size() == std::size(media::kLegacyFairPlaySystemId) &&
+         std::equal(system_id.begin(), system_id.end(),
+                    media::kLegacyFairPlaySystemId);
+}
+
 bool IsPlayReadySystemId(const std::vector<uint8_t>& system_id) {
   return system_id.size() == std::size(media::kPlayReadySystemId) &&
          std::equal(system_id.begin(), system_id.end(),
@@ -462,7 +468,7 @@ bool SimpleHlsNotifier::NotifyEncryptionUpdate(
                                     iv, "identity", "", media_playlist.get());
     return true;
   }
-  if (IsFairPlaySystemId(system_id)) {
+  if (IsFairPlaySystemId(system_id) || IsLegacyFairPlaySystemId(system_id)) {
     std::string key_uri = hls_params().key_uri;
     if (key_uri.empty()) {
       // Use key_id as the key_uri. The player needs to have custom logic to
diff --git a/packager/media/base/protection_system_ids.h b/packager/media/base/protection_system_ids.h
index 92dd923565..5ddaf8cb07 100644
--- a/packager/media/base/protection_system_ids.h
+++ b/packager/media/base/protection_system_ids.h
@@ -23,6 +23,12 @@ const uint8_t kFairPlaySystemId[] = {0x94, 0xCE, 0x86, 0xFB, 0x07, 0xFF,
                                      0x4F, 0x43, 0xAD, 0xB8, 0x93, 0xD2,
                                      0xFA, 0x96, 0x8C, 0xA2};
 
+// this is a legacy system ID used for FairPlay in old packager versions, kept
+// for backwards compatibility only
+const uint8_t kLegacyFairPlaySystemId[] = {0x29, 0x70, 0x1F, 0xE4, 0x3C, 0xC7,
+                                           0x4A, 0x34, 0x8C, 0x5B, 0xAE, 0x90,
+                                           0xC7, 0x43, 0x9A, 0x47};
+
 // Marlin Adaptive Streaming Specification – Simple Profile, V1.0.
 const uint8_t kMarlinSystemId[] = {0x5E, 0x62, 0x9A, 0xF5, 0x38, 0xDA,
                                    0x40, 0x63, 0x89, 0x77, 0x97, 0xFF,