diff --git a/utils/LocHeap.cpp b/utils/LocHeap.cpp
index 41268789..d667f14f 100644
--- a/utils/LocHeap.cpp
+++ b/utils/LocHeap.cpp
@@ -199,7 +199,7 @@ bool LocHeapNode::checkNodes() {
     int totalSize = mSize;
     if (mLeft) {
         // check the consistency of left subtree
-        if (!outRanks(*mLeft) || !mLeft->checkNodes()) {
+        if (mLeft->outRanks(*this) || !mLeft->checkNodes()) {
             return false;
         }
         // subtract the size of left subtree (with subtree head)
@@ -208,7 +208,7 @@ bool LocHeapNode::checkNodes() {
 
     if (mRight) {
         // check the consistency of right subtree
-        if (!outRanks(*mRight) || !mRight->checkNodes()) {
+        if (mRight->outRanks(*this) || !mRight->checkNodes()) {
             return false;
         }
         // subtract the size of right subtree (with subtree head)
diff --git a/utils/LocTimer.cpp b/utils/LocTimer.cpp
index 53ca700d..0f698c54 100644
--- a/utils/LocTimer.cpp
+++ b/utils/LocTimer.cpp
@@ -349,8 +349,12 @@ void LocTimerContainer::remove(LocTimerDelegate& timer) {
             LocMsg(), mTimerContainer(&container), mTimer(&timer) {}
         inline virtual void proc() const {
             LocTimerDelegate* priorTop = mTimerContainer->getSoonestTimer();
-            if (NULL != ((LocHeap*)mTimerContainer)->remove((LocRankable&)*mTimer)) {
-                mTimerContainer->updateSoonestTime(priorTop);
+            // update soonest timer only if mTimer is actually removed from mTimerContainer
+            // AND mTimer is not priorTop.
+            if (priorTop == ((LocHeap*)mTimerContainer)->remove((LocRankable&)*mTimer)) {
+                // if passing in NULL, we tell updateSoonestTime to update kernel with
+                // the current top timer interval.
+                mTimerContainer->updateSoonestTime(NULL);
             }
             delete mTimer;
         }