diff --git a/doc/ApiChanges.txt b/doc/ApiChanges.txt
index aa20adff..6353d976 100644
--- a/doc/ApiChanges.txt
+++ b/doc/ApiChanges.txt
@@ -16,6 +16,29 @@
 
 This file summarizes STA API changes for each release.
 
+The following iterator functions are deprecated:
+
+ TimingArcSet::timingArcIterator()
+ Sdc::clockIterator()
+
+Use the iterator class constructor instead. This avoids new/deletes of
+the iterators by stack allocating them. For example,
+Instead of
+
+  TimingArcSetArcIterator *arc_iter = arc_set->timingArcIterator();
+  while (arc_iter->hasNext()) {
+    TimingArc *arc = arc_iter->next();
+  }
+  delete arc_iter;
+
+use the following:
+
+  TimingArcSetArcIterator arc_iter(arc_set);
+  while (arc_iter.hasNext()) {
+    TimingArc *arc = arc_iter.next();
+  }
+
+
 Release 2.0.17 2019/11/11
 -------------------------
 
diff --git a/liberty/TimingArc.hh b/liberty/TimingArc.hh
index 7bf129a7..30774369 100644
--- a/liberty/TimingArc.hh
+++ b/liberty/TimingArc.hh
@@ -159,7 +159,8 @@ public:
 		TimingArc *&arc1,
 		TimingArc *&arc2);
   const TimingArcSeq &arcs() const { return arcs_; }
-  TimingArcSetArcIterator *timingArcIterator();
+  // Use the TimingArcSetArcIterator(arc_set) constructor instead.
+  TimingArcSetArcIterator *timingArcIterator() __attribute__ ((deprecated));
   TimingArcIndex addTimingArc(TimingArc *arc);
   void deleteTimingArc(TimingArc *arc);
   TimingArc *findTimingArc(unsigned arc_index);
diff --git a/sdc/Sdc.hh b/sdc/Sdc.hh
index 4fa9cd89..c5d7aae2 100644
--- a/sdc/Sdc.hh
+++ b/sdc/Sdc.hh
@@ -833,7 +833,7 @@ public:
   // Find the clocks defined for pin.
   ClockSet *findClocks(const Pin *pin) const;
   ClockSet *findLeafPinClocks(const Pin *pin) const;
-  ClockIterator *clockIterator();
+  ClockIterator *clockIterator() __attribute__ ((deprecated));
   void sortedClocks(ClockSeq &clks);
   ClockSeq *clocks() { return &clocks_; }
   ClockSeq &clks() { return clocks_; }