diff --git a/src/activation.cpp b/src/activation.cpp
index af56f28..37610c0 100644
--- a/src/activation.cpp
+++ b/src/activation.cpp
@@ -154,15 +154,6 @@
                             entry("VERSION_ID=%s", versionId.c_str()));
         return activation(); // Return the previous activation status
     }
-    if (!activationProgress)
-    {
-        activationProgress = std::make_unique<ActivationProgress>(bus, objPath);
-    }
-    if (!activationBlocksTransition)
-    {
-        activationBlocksTransition =
-            std::make_unique<ActivationBlocksTransition>(bus, objPath);
-    }
 
     auto psuPaths = utils::getPSUInventoryPath(bus);
     if (psuPaths.empty())
@@ -196,6 +187,16 @@
         return activation(); // Return the previous activation status
     }
 
+    if (!activationProgress)
+    {
+        activationProgress = std::make_unique<ActivationProgress>(bus, objPath);
+    }
+    if (!activationBlocksTransition)
+    {
+        activationBlocksTransition =
+            std::make_unique<ActivationBlocksTransition>(bus, objPath);
+    }
+
     // The progress to be increased for each successful update of PSU
     // E.g. in case we have 4 PSUs:
     //   1. Initial progrss is 10
@@ -336,6 +337,26 @@
     return service;
 }
 
+void ActivationBlocksTransition::enableRebootGuard()
+{
+    log<level::INFO>("PSU image activating - BMC reboots are disabled.");
+
+    auto method = bus.new_method_call(SYSTEMD_BUSNAME, SYSTEMD_PATH,
+                                      SYSTEMD_INTERFACE, "StartUnit");
+    method.append("reboot-guard-enable.service", "replace");
+    bus.call_noreply_noerror(method);
+}
+
+void ActivationBlocksTransition::disableRebootGuard()
+{
+    log<level::INFO>("PSU activation has ended - BMC reboots are re-enabled.");
+
+    auto method = bus.new_method_call(SYSTEMD_BUSNAME, SYSTEMD_PATH,
+                                      SYSTEMD_INTERFACE, "StartUnit");
+    method.append("reboot-guard-disable.service", "replace");
+    bus.call_noreply_noerror(method);
+}
+
 } // namespace updater
 } // namespace software
 } // namespace phosphor
diff --git a/src/activation.hpp b/src/activation.hpp
index 3b03803..bc95065 100644
--- a/src/activation.hpp
+++ b/src/activation.hpp
@@ -51,12 +51,14 @@
     {
         std::vector<std::string> interfaces({interface});
         bus.emit_interfaces_added(path.c_str(), interfaces);
+        enableRebootGuard();
     }
 
     ~ActivationBlocksTransition()
     {
         std::vector<std::string> interfaces({interface});
         bus.emit_interfaces_removed(path.c_str(), interfaces);
+        disableRebootGuard();
     }
 
   private:
@@ -65,6 +67,12 @@
         "xyz.openbmc_project.Software.ActivationBlocksTransition";
     sdbusplus::bus::bus& bus;
     std::string path;
+
+    /** @brief Enables a Guard that blocks any BMC reboot commands */
+    void enableRebootGuard();
+
+    /** @brief Disables any guard that was blocking the BMC reboot */
+    void disableRebootGuard();
 };
 
 using ActivationProgressInherit = sdbusplus::server::object::object<
diff --git a/test/test_item_updater.cpp b/test/test_item_updater.cpp
index b2cb62a..6b92e38 100644
--- a/test/test_item_updater.cpp
+++ b/test/test_item_updater.cpp
@@ -677,7 +677,8 @@
         .WillByDefault(Return(false));
     EXPECT_CALL(sdbusMock, sd_bus_message_new_method_call(_, _, _, _, _,
                                                           StrEq("StartUnit")))
-        .Times(1);
+        .Times(3); // There are 3 systemd units are started, enable bmc reboot
+                   // guard, start activation, and disable bmc reboot guard
     onPsuInventoryChanged(psuPath, propAdded);
     onPsuInventoryChanged(psuPath, propModel);
 }