diff --git a/.github/workflows/unit.yml b/.github/workflows/unit.yml
index d7d11c790..bb0e9d826 100644
--- a/.github/workflows/unit.yml
+++ b/.github/workflows/unit.yml
@@ -79,7 +79,7 @@ jobs:
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
         sudo apt-get --no-install-recommends install -y ninja-build lcov
     - name: Build Simulation
-      run: ./script/cmake-build simulation -DOT_BUILD_GTEST=ON -DOT_BORDER_ROUTING=ON -DOT_NCP_INFRA_IF=ON
+      run: ./script/cmake-build simulation -DOT_BUILD_GTEST=ON -DOT_BORDER_ROUTING=ON -DOT_BORDER_ROUTING_DHCP6_PD=ON -DOT_NCP_INFRA_IF=ON
     - name: Test Simulation
       run: cd build/simulation && ninja test
     - name: Build Multipan Simulation
diff --git a/src/core/border_router/routing_manager.cpp b/src/core/border_router/routing_manager.cpp
index df7a9beab..3f4d065df 100644
--- a/src/core/border_router/routing_manager.cpp
+++ b/src/core/border_router/routing_manager.cpp
@@ -4068,7 +4068,7 @@ void RoutingManager::PdPrefixManager::Process(const RouterAdvert::Icmp6Packet *a
         Get<RoutingManager>().ScheduleRoutingPolicyEvaluation(kImmediately);
     }
 
-    if (HasPrefix() && currentPrefixUpdated)
+    if (HasPrefix())
     {
         mTimer.FireAt(mPrefix.GetDeprecationTime());
     }
diff --git a/tests/unit/test_routing_manager.cpp b/tests/unit/test_routing_manager.cpp
index 4e65383f5..44fa71115 100644
--- a/tests/unit/test_routing_manager.cpp
+++ b/tests/unit/test_routing_manager.cpp
@@ -4287,6 +4287,57 @@ void TestBorderRoutingProcessPlatfromGeneratedNd(void)
         VerifyOmrPrefixInNetData(localOmr, /* aDefaultRoute */ false);
     }
 
+    // 6. Replace a prefix, on some platforms, there might be no messages to deprecate the old prefix, instead, they
+    // send new prefixes directly.
+    //    In this case, we still use the old prefix as long as the old prefix preferred lifetime is not exceeded, and
+    //    replace it with the new prefix when expired.
+    Log("6. Replace prefix.");
+    {
+        Ip6::Prefix raPrefix    = PrefixFromString("2001:db8:1:2::", 64);
+        Ip6::Prefix newRaPrefix = PrefixFromString("2001:db8:3:4::", 64);
+
+        SendRouterAdvertToBorderRoutingProcessIcmp6Ra({Pio(raPrefix, kValidLitime, kPreferredLifetime)});
+
+        sExpectedRios.Add(raPrefix);
+        sExpectedRios.Clear();
+        AdvanceTime(10 * 1000);
+
+        VerifyPdOmrPrefix(raPrefix);
+        VerifyOmrPrefixInNetData(raPrefix, /* aDefaultRoute */ false);
+
+        AdvanceTime(1000 * 1000);
+        VerifyPdOmrPrefix(raPrefix);
+
+        // Send new prefix without deprecating old prefix.
+        // The old prefix should be preferred for another (1800 - 10 - 1000) = 790s
+        SendRouterAdvertToBorderRoutingProcessIcmp6Ra({Pio(newRaPrefix, kValidLitime, kPreferredLifetime)});
+        AdvanceTime(500 * 1000);
+        VerifyPdOmrPrefix(raPrefix);
+
+        AdvanceTime(300 * 1000);
+        // Old Prefix should be removed now.
+        VerifyNoPdOmrPrefix();
+
+        sExpectedRios.Add(newRaPrefix);
+
+        // When the prefix is replaced, there will be a short period when the old prefix is still in the netdata, and PD
+        // manager will refuse to request the prefix.
+        SendRouterAdvertToBorderRoutingProcessIcmp6Ra({Pio(newRaPrefix, kValidLitime, kPreferredLifetime)});
+        // Advance a short period of time to wait for a stable PD state.
+        AdvanceTime(5000);
+        VerifyOrQuit(sInstance->Get<BorderRouter::RoutingManager>().GetDhcp6PdState() ==
+                     BorderRouter::RoutingManager::kDhcp6PdStateRunning);
+        SendRouterAdvertToBorderRoutingProcessIcmp6Ra({Pio(newRaPrefix, kValidLitime, kPreferredLifetime)});
+
+        AdvanceTime(1000 * 1000);
+        VerifyOrQuit(sExpectedRios.SawAll());
+        VerifyPdOmrPrefix(newRaPrefix);
+
+        AdvanceTime(1000 * 1000);
+        VerifyNoPdOmrPrefix();
+        VerifyOmrPrefixInNetData(localOmr, /* aDefaultRoute */ false);
+    }
+
     SuccessOrQuit(otBorderRoutingSetEnabled(sInstance, false));
     VerifyOrQuit(sHeapAllocatedPtrs.GetLength() <= heapAllocations);