diff --git a/common/error_code.h b/common/error_code.h
index adae391..0b08005 100644
--- a/common/error_code.h
+++ b/common/error_code.h
@@ -74,7 +74,7 @@
   kUserCanceled = 48,
   kNonCriticalUpdateInOOBE = 49,
   // kOmahaUpdateIgnoredOverCellular = 50,
-  // kPayloadTimestampError = 51,
+  kPayloadTimestampError = 51,
   kUpdatedButNotActive = 52,
 
   // VERY IMPORTANT! When adding new error codes:
diff --git a/common/error_code_utils.cc b/common/error_code_utils.cc
index 983d004..313a15f 100644
--- a/common/error_code_utils.cc
+++ b/common/error_code_utils.cc
@@ -144,6 +144,8 @@
       return "ErrorCode::kUserCanceled";
     case ErrorCode::kNonCriticalUpdateInOOBE:
       return "ErrorCode::kNonCriticalUpdateInOOBE";
+    case ErrorCode::kPayloadTimestampError:
+      return "ErrorCode::kPayloadTimestampError";
     case ErrorCode::kUpdatedButNotActive:
       return "ErrorCode::kUpdatedButNotActive";
       // Don't add a default case to let the compiler warn about newly added
diff --git a/common/fake_hardware.h b/common/fake_hardware.h
index 01d23d0..f2b2c9d 100644
--- a/common/fake_hardware.h
+++ b/common/fake_hardware.h
@@ -81,6 +81,8 @@
     return false;
   }
 
+  int64_t GetBuildTimestamp() const override { return build_timestamp_; }
+
   bool GetFirstActiveOmahaPingSent() const override {
     return first_active_omaha_ping_sent_;
   }
@@ -133,6 +135,10 @@
     powerwash_count_ = powerwash_count;
   }
 
+  void SetBuildTimestamp(int64_t build_timestamp) {
+    build_timestamp_ = build_timestamp;
+  }
+
  private:
   bool is_official_build_{true};
   bool is_normal_boot_mode_{true};
@@ -145,6 +151,7 @@
   std::string ec_version_{"Fake EC v1.0a"};
   int powerwash_count_{kPowerwashCountNotSet};
   bool powerwash_scheduled_{false};
+  int64_t build_timestamp_{0};
   bool first_active_omaha_ping_sent_{false};
 
   DISALLOW_COPY_AND_ASSIGN(FakeHardware);
diff --git a/common/hardware_interface.h b/common/hardware_interface.h
index 541a68a..94442d1 100644
--- a/common/hardware_interface.h
+++ b/common/hardware_interface.h
@@ -17,6 +17,8 @@
 #ifndef UPDATE_ENGINE_COMMON_HARDWARE_INTERFACE_H_
 #define UPDATE_ENGINE_COMMON_HARDWARE_INTERFACE_H_
 
+#include <stdint.h>
+
 #include <string>
 #include <vector>
 
@@ -90,6 +92,9 @@
   // returns false.
   virtual bool GetPowerwashSafeDirectory(base::FilePath* path) const = 0;
 
+  // Returns the timestamp of the current OS build.
+  virtual int64_t GetBuildTimestamp() const = 0;
+
   // Returns whether the first active ping was sent to Omaha at some point, and
   // that the value is persisted across recovery (and powerwash) once set with
   // |SetFirstActiveOmahaPingSent()|.
diff --git a/hardware_android.cc b/hardware_android.cc
index 58c68b6..947b13a 100644
--- a/hardware_android.cc
+++ b/hardware_android.cc
@@ -35,6 +35,7 @@
 #include "update_engine/utils_android.h"
 
 using android::base::GetBoolProperty;
+using android::base::GetIntProperty;
 using android::base::GetProperty;
 using std::string;
 
@@ -56,6 +57,7 @@
 const char kPropProductManufacturer[] = "ro.product.manufacturer";
 const char kPropBootHardwareSKU[] = "ro.boot.hardware.sku";
 const char kPropBootRevision[] = "ro.boot.revision";
+const char kPropBuildDateUTC[] = "ro.build.date.utc";
 
 // Write a recovery command line |message| to the BCB. The arguments to recovery
 // must be separated by '\n'. An empty string will erase the BCB.
@@ -194,6 +196,10 @@
   return false;
 }
 
+int64_t HardwareAndroid::GetBuildTimestamp() const {
+  return GetIntProperty<int64_t>(kPropBuildDateUTC, 0);
+}
+
 bool HardwareAndroid::GetFirstActiveOmahaPingSent() const {
   LOG(WARNING) << "STUB: Assuming first active omaha was never set.";
   return false;
diff --git a/hardware_android.h b/hardware_android.h
index 37393ce..ca90b62 100644
--- a/hardware_android.h
+++ b/hardware_android.h
@@ -47,6 +47,7 @@
   bool CancelPowerwash() override;
   bool GetNonVolatileDirectory(base::FilePath* path) const override;
   bool GetPowerwashSafeDirectory(base::FilePath* path) const override;
+  int64_t GetBuildTimestamp() const override;
   bool GetFirstActiveOmahaPingSent() const override;
   void SetFirstActiveOmahaPingSent() override;
 
diff --git a/hardware_chromeos.cc b/hardware_chromeos.cc
index 8c19aa7..f2bb28a 100644
--- a/hardware_chromeos.cc
+++ b/hardware_chromeos.cc
@@ -231,6 +231,11 @@
   return true;
 }
 
+int64_t HardwareChromeOS::GetBuildTimestamp() const {
+  // TODO(senj): implement this in Chrome OS.
+  return 0;
+}
+
 void HardwareChromeOS::LoadConfig(const string& root_prefix, bool normal_mode) {
   brillo::KeyValueStore store;
 
diff --git a/hardware_chromeos.h b/hardware_chromeos.h
index 3a0bba2..0cf1214 100644
--- a/hardware_chromeos.h
+++ b/hardware_chromeos.h
@@ -51,6 +51,7 @@
   bool CancelPowerwash() override;
   bool GetNonVolatileDirectory(base::FilePath* path) const override;
   bool GetPowerwashSafeDirectory(base::FilePath* path) const override;
+  int64_t GetBuildTimestamp() const override;
   bool GetFirstActiveOmahaPingSent() const override;
   void SetFirstActiveOmahaPingSent() override;
 
diff --git a/metrics_utils.cc b/metrics_utils.cc
index 7e6b20f..46530f0 100644
--- a/metrics_utils.cc
+++ b/metrics_utils.cc
@@ -78,6 +78,7 @@
     case ErrorCode::kDownloadPayloadVerificationError:
     case ErrorCode::kSignedDeltaPayloadExpectedError:
     case ErrorCode::kDownloadPayloadPubKeyVerificationError:
+    case ErrorCode::kPayloadTimestampError:
       return metrics::AttemptResult::kPayloadVerificationFailed;
 
     case ErrorCode::kNewRootfsVerificationError:
@@ -213,6 +214,7 @@
     case ErrorCode::kOmahaRequestXMLHasEntityDecl:
     case ErrorCode::kFilesystemVerifierError:
     case ErrorCode::kUserCanceled:
+    case ErrorCode::kPayloadTimestampError:
     case ErrorCode::kUpdatedButNotActive:
       break;
 
diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index a392b40..338008f 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -1638,6 +1638,14 @@
     }
   }
 
+  if (manifest_.max_timestamp() < hardware_->GetBuildTimestamp()) {
+    LOG(ERROR) << "The current OS build timestamp ("
+               << hardware_->GetBuildTimestamp()
+               << ") is newer than the maximum timestamp in the manifest ("
+               << manifest_.max_timestamp() << ")";
+    return ErrorCode::kPayloadTimestampError;
+  }
+
   // TODO(garnold) we should be adding more and more manifest checks, such as
   // partition boundaries etc (see chromium-os:37661).
 
diff --git a/payload_consumer/delta_performer_unittest.cc b/payload_consumer/delta_performer_unittest.cc
index 092327b..420efd2 100644
--- a/payload_consumer/delta_performer_unittest.cc
+++ b/payload_consumer/delta_performer_unittest.cc
@@ -721,6 +721,20 @@
                         ErrorCode::kUnsupportedMinorPayloadVersion);
 }
 
+TEST_F(DeltaPerformerTest, ValidateManifestDowngrade) {
+  // The Manifest we are validating.
+  DeltaArchiveManifest manifest;
+
+  manifest.set_minor_version(kFullPayloadMinorVersion);
+  manifest.set_max_timestamp(1);
+  fake_hardware_.SetBuildTimestamp(2);
+
+  RunManifestValidation(manifest,
+                        DeltaPerformer::kSupportedMajorPayloadVersion,
+                        InstallPayloadType::kFull,
+                        ErrorCode::kPayloadTimestampError);
+}
+
 TEST_F(DeltaPerformerTest, BrilloMetadataSignatureSizeTest) {
   EXPECT_TRUE(performer_.Write(kDeltaMagic, sizeof(kDeltaMagic)));
 
diff --git a/payload_generator/generate_delta_main.cc b/payload_generator/generate_delta_main.cc
index a20a567..2729bc4 100644
--- a/payload_generator/generate_delta_main.cc
+++ b/payload_generator/generate_delta_main.cc
@@ -335,6 +335,10 @@
   DEFINE_string(properties_file, "",
                 "If passed, dumps the payload properties of the payload passed "
                 "in --in_file and exits.");
+  DEFINE_int64(max_timestamp,
+               0,
+               "The maximum timestamp of the OS allowed to apply this "
+               "payload.");
 
   DEFINE_string(old_channel, "",
                 "The channel for the old image. 'dev-channel', 'npo-channel', "
@@ -576,6 +580,8 @@
     LOG(INFO) << "Using provided minor_version=" << FLAGS_minor_version;
   }
 
+  payload_config.max_timestamp = FLAGS_max_timestamp;
+
   LOG(INFO) << "Generating " << (payload_config.is_delta ? "delta" : "full")
             << " update";
 
diff --git a/payload_generator/payload_file.cc b/payload_generator/payload_file.cc
index 941b640..f48d2a2 100644
--- a/payload_generator/payload_file.cc
+++ b/payload_generator/payload_file.cc
@@ -73,6 +73,7 @@
     *(manifest_.mutable_new_image_info()) = config.target.image_info;
 
   manifest_.set_block_size(config.block_size);
+  manifest_.set_max_timestamp(config.max_timestamp);
   return true;
 }
 
diff --git a/payload_generator/payload_generation_config.h b/payload_generator/payload_generation_config.h
index ca6fb04..c553d29 100644
--- a/payload_generator/payload_generation_config.h
+++ b/payload_generator/payload_generation_config.h
@@ -186,6 +186,9 @@
 
   // The block size used for all the operations in the manifest.
   size_t block_size = 4096;
+
+  // The maximum timestamp of the OS allowed to apply this payload.
+  int64_t max_timestamp = 0;
 };
 
 }  // namespace chromeos_update_engine
diff --git a/payload_state.cc b/payload_state.cc
index cff02b1..4992606 100644
--- a/payload_state.cc
+++ b/payload_state.cc
@@ -305,6 +305,7 @@
     case ErrorCode::kPayloadMismatchedType:
     case ErrorCode::kUnsupportedMajorPayloadVersion:
     case ErrorCode::kUnsupportedMinorPayloadVersion:
+    case ErrorCode::kPayloadTimestampError:
       IncrementUrlIndex();
       break;
 
diff --git a/scripts/brillo_update_payload b/scripts/brillo_update_payload
index 61ecadf..65c63f5 100755
--- a/scripts/brillo_update_payload
+++ b/scripts/brillo_update_payload
@@ -167,6 +167,10 @@
     "Optional: Path to a source image. If specified, this makes a delta update."
   DEFINE_string metadata_size_file "" \
     "Optional: Path to output metadata size."
+  DEFINE_string max_timestamp "" \
+    "Optional: The maximum unix timestamp of the OS allowed to apply this \
+payload, should be set to a number higher than the build timestamp of the \
+system running on the device, 0 if not specified."
 fi
 if [[ "${COMMAND}" == "hash" || "${COMMAND}" == "sign" ]]; then
   DEFINE_string unsigned_payload "" "Path to the input unsigned payload."
@@ -567,6 +571,10 @@
     GENERATOR_ARGS+=( --out_metadata_size_file="${FLAGS_metadata_size_file}" )
   fi
 
+  if [[ -n "${FLAGS_max_timestamp}" ]]; then
+    GENERATOR_ARGS+=( --max_timestamp="${FLAGS_max_timestamp}" )
+  fi
+
   if [[ -n "${POSTINSTALL_CONFIG_FILE}" ]]; then
     GENERATOR_ARGS+=(
       --new_postinstall_config_file="${POSTINSTALL_CONFIG_FILE}"
diff --git a/update_attempter_android.cc b/update_attempter_android.cc
index 5ee0584..aacb06b 100644
--- a/update_attempter_android.cc
+++ b/update_attempter_android.cc
@@ -29,6 +29,7 @@
 #include <brillo/data_encoding.h>
 #include <brillo/message_loops/message_loop.h>
 #include <brillo/strings/string_utils.h>
+#include <log/log_safetynet.h>
 
 #include "update_engine/common/constants.h"
 #include "update_engine/common/file_fetcher.h"
@@ -350,6 +351,11 @@
       LOG(INFO) << "Resetting update progress.";
       break;
 
+    case ErrorCode::kPayloadTimestampError:
+      // SafetyNet logging, b/36232423
+      android_errorWriteLog(0x534e4554, "36232423");
+      break;
+
     default:
       // Ignore all other error codes.
       break;
diff --git a/update_manager/chromeos_policy.cc b/update_manager/chromeos_policy.cc
index 12f417c..b32b626 100644
--- a/update_manager/chromeos_policy.cc
+++ b/update_manager/chromeos_policy.cc
@@ -79,6 +79,7 @@
     case ErrorCode::kPayloadMismatchedType:
     case ErrorCode::kUnsupportedMajorPayloadVersion:
     case ErrorCode::kUnsupportedMinorPayloadVersion:
+    case ErrorCode::kPayloadTimestampError:
       LOG(INFO) << "Advancing download URL due to error "
                 << chromeos_update_engine::utils::ErrorCodeToString(err_code)
                 << " (" << static_cast<int>(err_code) << ")";
diff --git a/update_metadata.proto b/update_metadata.proto
index ad377c7..b5d6c59 100644
--- a/update_metadata.proto
+++ b/update_metadata.proto
@@ -288,4 +288,8 @@
   // array can have more than two partitions if needed, and they are identified
   // by the partition name.
   repeated PartitionUpdate partitions = 13;
+
+  // The maximum timestamp of the OS allowed to apply this payload.
+  // Can be used to prevent downgrading the OS.
+  optional int64 max_timestamp = 14;
 }