diff --git a/script/make-pretty b/script/make-pretty
index 5150d54da..7d6061198 100755
--- a/script/make-pretty
+++ b/script/make-pretty
@@ -126,6 +126,7 @@ modernize-use-nullptr,\
 readability-avoid-const-params-in-decls,\
 readability-make-member-function-const,\
 readability-simplify-boolean-expr,\
+readability-static-accessed-through-instance,\
 "
 
 #performance-for-range-copy\
diff --git a/src/core/mac/mac.cpp b/src/core/mac/mac.cpp
index ec5b24ca2..cc981f71d 100644
--- a/src/core/mac/mac.cpp
+++ b/src/core/mac/mac.cpp
@@ -577,7 +577,7 @@ void Mac::RequestCslFrameTransmission(uint32_t aDelay)
 {
     VerifyOrExit(mEnabled);
 
-    mCslTxFireTime = mTimer.GetNow() + aDelay;
+    mCslTxFireTime = TimerMilli::GetNow() + aDelay;
 
     StartOperation(kOperationTransmitDataCsl);
 
@@ -785,7 +785,7 @@ void Mac::PerformNextOperation(void)
         mOperation             = kOperationWaitingForData;
     }
 #if OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
-    else if (mPendingTransmitDataCsl && mTimer.GetNow() >= mCslTxFireTime)
+    else if (mPendingTransmitDataCsl && TimerMilli::GetNow() >= mCslTxFireTime)
     {
         mPendingTransmitDataCsl = false;
         mOperation              = kOperationTransmitDataCsl;
@@ -2456,7 +2456,7 @@ void Mac::UpdateFrameControlField(const Neighbor *aNeighbor, bool aIsTimeSync, u
     else
 #endif
 #if OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
-        if (aNeighbor != nullptr && !Get<Mle::MleRouter>().IsActiveRouter(aNeighbor->GetRloc16()) &&
+        if (aNeighbor != nullptr && !Mle::MleRouter::IsActiveRouter(aNeighbor->GetRloc16()) &&
             static_cast<const Child *>(aNeighbor)->IsCslSynchronized())
     {
         aFcf |= Frame::kFcfFrameVersion2015;
diff --git a/src/core/mac/sub_mac.cpp b/src/core/mac/sub_mac.cpp
index 0bdf01c9c..3424f118d 100644
--- a/src/core/mac/sub_mac.cpp
+++ b/src/core/mac/sub_mac.cpp
@@ -940,7 +940,7 @@ void SubMac::SetCslPeriod(uint16_t aPeriod)
 
     if (mCslPeriod > 0)
     {
-        mCslSampleTime = mCslTimer.GetNow();
+        mCslSampleTime = TimerMicro::GetNow();
         Get<Radio>().UpdateCslSampleTime(mCslSampleTime.GetValue());
 
         mCslState = kCslSample;
diff --git a/src/core/thread/mesh_forwarder_ftd.cpp b/src/core/thread/mesh_forwarder_ftd.cpp
index 4601c7edc..a9055ac38 100644
--- a/src/core/thread/mesh_forwarder_ftd.cpp
+++ b/src/core/thread/mesh_forwarder_ftd.cpp
@@ -905,7 +905,7 @@ otError MeshForwarder::GetDestinationRlocByServiceAloc(uint16_t aServiceAloc, ui
                 // Path cost
                 curCost = Get<Mle::MleRouter>().GetCost(server16);
 
-                if (!Get<Mle::MleRouter>().IsActiveRouter(server16))
+                if (!Mle::MleRouter::IsActiveRouter(server16))
                 {
                     // Assume best link between remote child server and its parent.
                     curCost += 1;
@@ -918,7 +918,7 @@ otError MeshForwarder::GetDestinationRlocByServiceAloc(uint16_t aServiceAloc, ui
                 {
                     uint8_t cost;
 
-                    if (!Get<Mle::MleRouter>().IsActiveRouter(server16))
+                    if (!Mle::MleRouter::IsActiveRouter(server16))
                     {
                         // Cost calculated only from Link Quality In as the parent only maintains
                         // one-direction link info.