diff --git a/configure.ac b/configure.ac
index ae9d6e8..0cbc673 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,6 +69,12 @@
     AC_SUBST([OESDK_TESTCASE_FLAGS], [$testcase_flags])
 )
 
+# The continuous integration tests set this.
+# Use it to know where to store logs.
+AC_ARG_ENABLE([tests],
+    AS_HELP_STRING([--enable-tests], [Specifies running in the CI environment])
+)
+
 AC_DEFINE(BUSNAME_LOGGING, "xyz.openbmc_project.Logging", [The log manager DBus busname to own.])
 AC_DEFINE(OBJ_LOGGING, "/xyz/openbmc_project/logging", [The log manager DBus object path.])
 AC_DEFINE(OBJ_INTERNAL, "/xyz/openbmc_project/logging/internal/manager", [The private log manager DBus object path.])
@@ -80,6 +86,9 @@
 AC_DEFINE(FIRST_CEREAL_CLASS_VERSION_WITH_FWLEVEL, "2",
           [First Cereal class version with the BMC code version persisted])
 
+AC_DEFINE(FIRST_CEREAL_CLASS_VERSION_WITH_UPDATE_TS, "3",
+          [First Cereal class version with the update timestamp persisted])
+
 AC_ARG_VAR(YAML_DIR_TEST, [The path to the test error yaml files.])
 AS_IF([test "x$YAML_DIR_TEST" == "x"], \
     [YAML_DIR_TEST="${srcdir}/tools/"])
@@ -96,6 +105,8 @@
         [ERRLOG_PERSIST_PATH="/tmp/errors"])
     AS_IF([test "x$enable_oe_sdk" == "x"], \
         [ERRLOG_PERSIST_PATH="/var/lib/phosphor-logging/errors"])
+    AS_IF([test "x$enable_tests" == "xyes"], \
+        [ERRLOG_PERSIST_PATH="/tmp/errors"])
     AC_DEFINE_UNQUOTED([ERRLOG_PERSIST_PATH], ["$ERRLOG_PERSIST_PATH"], \
         [Path of directory housing persisted errors])
 )
@@ -116,7 +127,7 @@
     [Cap on informational (and below) severity errors])
 
 AC_ARG_VAR(CLASS_VERSION, [Class version to register with Cereal])
-AS_IF([test "x$CLASS_VERSION" == "x"], [CLASS_VERSION=2])
+AS_IF([test "x$CLASS_VERSION" == "x"], [CLASS_VERSION=3])
 AC_DEFINE_UNQUOTED([CLASS_VERSION], [$CLASS_VERSION], [Class version to register with Cereal])
 
 AC_ARG_VAR(RSYSLOG_SERVER_CONFIG_FILE, \
diff --git a/elog_entry.cpp b/elog_entry.cpp
index 04aa917..36a3fb2 100644
--- a/elog_entry.cpp
+++ b/elog_entry.cpp
@@ -25,6 +25,12 @@
         current =
             sdbusplus::xyz::openbmc_project::Logging::server::Entry::resolved(
                 value);
+
+        uint64_t ms = std::chrono::duration_cast<std::chrono::milliseconds>(
+                          std::chrono::system_clock::now().time_since_epoch())
+                          .count();
+        updateTimestamp(ms);
+
         serialize(*this);
     }
 
diff --git a/elog_entry.hpp b/elog_entry.hpp
index 9c93afe..5bc4882 100644
--- a/elog_entry.hpp
+++ b/elog_entry.hpp
@@ -68,6 +68,7 @@
         id(idErr);
         severity(severityErr);
         timestamp(timestampErr);
+        updateTimestamp(timestampErr);
         message(std::move(msgErr));
         additionalData(std::move(additionalDataErr));
         associations(std::move(objects));
diff --git a/elog_serialize.cpp b/elog_serialize.cpp
index 72534a4..40c6b74 100644
--- a/elog_serialize.cpp
+++ b/elog_serialize.cpp
@@ -30,7 +30,7 @@
 void save(Archive& a, const Entry& e, const std::uint32_t version)
 {
     a(e.id(), e.severity(), e.timestamp(), e.message(), e.additionalData(),
-      e.associations(), e.resolved(), e.version());
+      e.associations(), e.resolved(), e.version(), e.updateTimestamp());
 }
 
 /** @brief Function required by Cereal to perform deserialization.
@@ -53,16 +53,24 @@
     bool resolved{};
     AssociationList associations{};
     std::string fwVersion{};
+    uint64_t updateTimestamp{};
 
     if (version < std::stoul(FIRST_CEREAL_CLASS_VERSION_WITH_FWLEVEL))
     {
         a(id, severity, timestamp, message, additionalData, associations,
           resolved);
+        updateTimestamp = timestamp;
+    }
+    else if (version < std::stoul(FIRST_CEREAL_CLASS_VERSION_WITH_UPDATE_TS))
+    {
+        a(id, severity, timestamp, message, additionalData, associations,
+          resolved, fwVersion);
+        updateTimestamp = timestamp;
     }
     else
     {
         a(id, severity, timestamp, message, additionalData, associations,
-          resolved, fwVersion);
+          resolved, fwVersion, updateTimestamp);
     }
 
     e.id(id);
@@ -76,6 +84,7 @@
     e.version(fwVersion);
     e.purpose(sdbusplus::xyz::openbmc_project::Software::server::Version::
                   VersionPurpose::BMC);
+    e.updateTimestamp(updateTimestamp);
 }
 
 fs::path serialize(const Entry& e, const fs::path& dir)
diff --git a/test/Makefile.am b/test/Makefile.am
index 64aa6d8..ddd42e6 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -10,7 +10,8 @@
 	remote_logging_test_port \
 	remote_logging_test_config \
 	sdjournal_mock_test \
-	extensions_test
+	extensions_test \
+	elog_update_ts_test
 
 test_cppflags = \
 	-Igtest \
@@ -106,6 +107,13 @@
 	$(top_builddir)/xyz/openbmc_project/Logging/Internal/Manager/server.o
 extensions_test_LDFLAGS = $(test_ldflags)
 
+elog_update_ts_test_CPPFLAGS = $(test_cppflags)
+elog_update_ts_test_CXXFLAGS = $(test_cxxflags)
+elog_update_ts_test_SOURCES = elog_update_ts_test.cpp
+elog_update_ts_test_LDADD = $(test_ldadd)
+elog_update_ts_test_LDFLAGS = \
+	$(test_ldflags)
+
 # TODO Remove once the test-case failure is resolved openbmc/phosphor-logging#11
 XFAIL_TESTS = elog_errorwrap_test
 
diff --git a/test/elog_update_ts_test.cpp b/test/elog_update_ts_test.cpp
new file mode 100644
index 0000000..ece0b80
--- /dev/null
+++ b/test/elog_update_ts_test.cpp
@@ -0,0 +1,73 @@
+#include "config.h"
+
+#include "elog_entry.hpp"
+#include "elog_serialize.hpp"
+#include "log_manager.hpp"
+
+#include <filesystem>
+#include <thread>
+
+#include <gtest/gtest.h>
+
+namespace phosphor
+{
+namespace logging
+{
+namespace test
+{
+
+using namespace std::chrono_literals;
+
+// Test that the update timestamp changes when the resolved property changes
+TEST(TestUpdateTS, testChangeResolved)
+{
+    // Setting resolved will serialize, so need this directory.
+    std::filesystem::create_directory(ERRLOG_PERSIST_PATH);
+
+    auto bus = sdbusplus::bus::new_default();
+    phosphor::logging::internal::Manager manager(bus, OBJ_INTERNAL);
+
+    uint32_t id = 99;
+    uint64_t timestamp{100};
+    std::string message{"test error"};
+    std::string fwLevel{"level42"};
+    std::vector<std::string> testData{"additional", "data"};
+    phosphor::logging::AssociationList associations{};
+
+    Entry elog{bus,
+               std::string(OBJ_ENTRY) + '/' + std::to_string(id),
+               id,
+               timestamp,
+               Entry::Level::Informational,
+               std::move(message),
+               std::move(testData),
+               std::move(associations),
+               fwLevel,
+               manager};
+
+    EXPECT_EQ(elog.timestamp(), elog.updateTimestamp());
+
+    std::this_thread::sleep_for(1ms);
+
+    elog.resolved(true);
+    auto updateTS = elog.updateTimestamp();
+    EXPECT_NE(updateTS, elog.timestamp());
+
+    std::this_thread::sleep_for(1ms);
+
+    elog.resolved(false);
+    EXPECT_NE(updateTS, elog.updateTimestamp());
+    updateTS = elog.updateTimestamp();
+
+    std::this_thread::sleep_for(1ms);
+
+    // No change
+    elog.resolved(false);
+    EXPECT_EQ(updateTS, elog.updateTimestamp());
+
+    std::filesystem::remove_all(ERRLOG_PERSIST_PATH);
+}
+
+} // namespace test
+} // namespace logging
+} // namespace phosphor
diff --git a/test/serialization_test_properties.cpp b/test/serialization_test_properties.cpp
index 8c92024..270f8bc 100644
--- a/test/serialization_test_properties.cpp
+++ b/test/serialization_test_properties.cpp
@@ -38,6 +38,7 @@
     EXPECT_EQ(input->associations(), output->associations());
     EXPECT_EQ(input->version(), output->version());
     EXPECT_EQ(input->purpose(), output->purpose());
+    EXPECT_EQ(input->updateTimestamp(), output->updateTimestamp());
 }
 
 } // namespace test