diff --git a/src/core/thread/mesh_forwarder.cpp b/src/core/thread/mesh_forwarder.cpp
index 4efa3d8e9..49a8aa285 100644
--- a/src/core/thread/mesh_forwarder.cpp
+++ b/src/core/thread/mesh_forwarder.cpp
@@ -612,17 +612,15 @@ Error MeshForwarder::UpdateIp6Route(Message &aMessage)
     {
         mMacAddrs.mDestination.SetExtendedFromIid(ip6Header.GetDestination().GetIid());
     }
-    else if (Get<Mle::Mle>().IsMinimalEndDevice())
+#if OPENTHREAD_FTD
+    else if (Get<Mle::Mle>().IsFullThreadDevice())
     {
-        mMacAddrs.mDestination.SetShort(Get<Mle::Mle>().GetParentRloc16());
+        error = UpdateIp6RouteFtd(ip6Header, aMessage);
     }
+#endif
     else
     {
-#if OPENTHREAD_FTD
-        error = UpdateIp6RouteFtd(ip6Header, aMessage);
-#else
-        OT_ASSERT(false);
-#endif
+        mMacAddrs.mDestination.SetShort(Get<Mle::Mle>().GetParentRloc16());
     }
 
 exit:
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index fb8c0da0b..1e62c5fbe 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -329,7 +329,7 @@ public:
     bool IsFullThreadDevice(void) const { return mDeviceMode.IsFullThreadDevice(); }
 
     /**
-     * Indicates whether or not the device is a Minimal End Device.
+     * Indicates whether or not the device is a Minimal End Device (MED), i.e., an MTD which is rx-on-when-idle.
      *
      * @returns TRUE if the device is a Minimal End Device, FALSE otherwise.
      */
diff --git a/src/core/thread/mle_types.hpp b/src/core/thread/mle_types.hpp
index da2868d11..80897cff7 100644
--- a/src/core/thread/mle_types.hpp
+++ b/src/core/thread/mle_types.hpp
@@ -452,15 +452,12 @@ public:
     }
 
     /**
-     * Indicates whether or not the device is a Minimal End Device.
+     * Indicates whether or not the device is a Minimal End Device (MED), i.e., an MTD which is rx-on-when-idle.
      *
      * @retval TRUE   If the device is a Minimal End Device.
      * @retval FALSE  If the device is not a Minimal End Device.
      */
-    bool IsMinimalEndDevice(void) const
-    {
-        return (mMode & (kModeFullThreadDevice | kModeRxOnWhenIdle)) != (kModeFullThreadDevice | kModeRxOnWhenIdle);
-    }
+    bool IsMinimalEndDevice(void) const { return !IsFullThreadDevice() && IsRxOnWhenIdle(); }
 
     /**
      * Indicates whether or not the device mode flags are valid.
diff --git a/tests/unit/test_mle.cpp b/tests/unit/test_mle.cpp
index 5bb720369..8e5a34b9d 100644
--- a/tests/unit/test_mle.cpp
+++ b/tests/unit/test_mle.cpp
@@ -36,6 +36,158 @@
 
 namespace ot {
 
+void TestDeviceMode(void)
+{
+    Mle::DeviceMode             mode;
+    Mle::DeviceMode::ModeConfig config;
+    Mle::DeviceMode::ModeConfig readConfig;
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // SED (stable subset netdata)
+    config.mRxOnWhenIdle = false;
+    config.mDeviceType   = false;
+    config.mNetworkData  = false;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(!readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(!readConfig.mDeviceType);
+    VerifyOrQuit(!readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(!mode.IsRxOnWhenIdle());
+    VerifyOrQuit(!mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kStableSubset);
+    VerifyOrQuit(!mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // SED (full set netdata)
+
+    config.mRxOnWhenIdle = false;
+    config.mDeviceType   = false;
+    config.mNetworkData  = true;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(!readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(!readConfig.mDeviceType);
+    VerifyOrQuit(readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(!mode.IsRxOnWhenIdle());
+    VerifyOrQuit(!mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kFullSet);
+    VerifyOrQuit(!mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // MED (stable subset netdata)
+
+    config.mRxOnWhenIdle = true;
+    config.mDeviceType   = false;
+    config.mNetworkData  = false;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(!readConfig.mDeviceType);
+    VerifyOrQuit(!readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(mode.IsRxOnWhenIdle());
+    VerifyOrQuit(!mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kStableSubset);
+    VerifyOrQuit(mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // MED (full set netdata)
+
+    config.mRxOnWhenIdle = true;
+    config.mDeviceType   = false;
+    config.mNetworkData  = true;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(!readConfig.mDeviceType);
+    VerifyOrQuit(readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(mode.IsRxOnWhenIdle());
+    VerifyOrQuit(!mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kFullSet);
+    VerifyOrQuit(mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // FTD (stable subset netdata)
+
+    config.mRxOnWhenIdle = true;
+    config.mDeviceType   = true;
+    config.mNetworkData  = false;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(readConfig.mDeviceType);
+    VerifyOrQuit(!readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(mode.IsRxOnWhenIdle());
+    VerifyOrQuit(mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kStableSubset);
+    VerifyOrQuit(!mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // FTD (full set netdata)
+
+    config.mRxOnWhenIdle = true;
+    config.mDeviceType   = true;
+    config.mNetworkData  = true;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(readConfig.mDeviceType);
+    VerifyOrQuit(readConfig.mNetworkData);
+
+    VerifyOrQuit(mode.IsValid());
+    VerifyOrQuit(mode.IsRxOnWhenIdle());
+    VerifyOrQuit(mode.IsFullThreadDevice());
+    VerifyOrQuit(mode.GetNetworkDataType() == NetworkData::kFullSet);
+    VerifyOrQuit(!mode.IsMinimalEndDevice());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // Invalid
+
+    config.mRxOnWhenIdle = false;
+    config.mDeviceType   = true;
+    config.mNetworkData  = true;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(!readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(readConfig.mDeviceType);
+    VerifyOrQuit(readConfig.mNetworkData);
+
+    VerifyOrQuit(!mode.IsValid());
+
+    //- - - - - - - - - - - - - - - - - - - - - - - -
+    // Invalid
+
+    config.mRxOnWhenIdle = false;
+    config.mDeviceType   = true;
+    config.mNetworkData  = false;
+    mode.Set(config);
+
+    mode.Get(readConfig);
+    VerifyOrQuit(!readConfig.mRxOnWhenIdle);
+    VerifyOrQuit(readConfig.mDeviceType);
+    VerifyOrQuit(!readConfig.mNetworkData);
+
+    VerifyOrQuit(!mode.IsValid());
+
+    printf("TestDeviceMode passed\n");
+}
+
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_MLE_DEVICE_PROPERTY_LEADER_WEIGHT_ENABLE
 
 void TestDefaultDeviceProperties(void)
@@ -176,6 +328,8 @@ void TestLeaderWeightCalculation(void)
 
 int main(void)
 {
+    ot::TestDeviceMode();
+
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_MLE_DEVICE_PROPERTY_LEADER_WEIGHT_ENABLE
     ot::TestDefaultDeviceProperties();
     ot::TestLeaderWeightCalculation();