diff --git a/include/sta/Liberty.hh b/include/sta/Liberty.hh
index 14dab380..5f10462c 100644
--- a/include/sta/Liberty.hh
+++ b/include/sta/Liberty.hh
@@ -423,6 +423,8 @@ public:
   void setIsMemory(bool is_memory);
   bool isPad() const { return is_pad_; }
   void setIsPad(bool is_pad);
+  bool isClockCell() const { return is_clock_cell_; }
+  void setIsClockCell(bool is_clock_cell);
   bool isLevelShifter() const { return is_level_shifter_; }
   void setIsLevelShifter(bool is_level_shifter);
   LevelShifterType levelShifterType() const { return level_shifter_type_; }
@@ -564,6 +566,7 @@ protected:
   bool is_macro_;
   bool is_memory_;
   bool is_pad_;
+  bool is_clock_cell_;
   bool is_level_shifter_;
   LevelShifterType level_shifter_type_;
   bool is_isolation_cell_;
diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index 6e8a91c0..1878f113 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -925,6 +925,7 @@ LibertyCell::LibertyCell(LibertyLibrary *library,
   is_macro_(false),
   is_memory_(false),
   is_pad_(false),
+  is_clock_cell_(false),
   is_level_shifter_(false),
   level_shifter_type_(LevelShifterType::HL_LH),
   is_isolation_cell_(false),
@@ -1077,6 +1078,12 @@ LibertyCell::LibertyCell::setIsPad(bool is_pad)
   is_pad_ = is_pad;
 }
 
+void
+LibertyCell::LibertyCell::setIsClockCell(bool is_clock_cell)
+{
+  is_clock_cell_ = is_clock_cell;
+}
+
 void
 LibertyCell::setIsLevelShifter(bool is_level_shifter)
 {
diff --git a/liberty/LibertyReader.cc b/liberty/LibertyReader.cc
index 7cf3491d..f25cc79f 100644
--- a/liberty/LibertyReader.cc
+++ b/liberty/LibertyReader.cc
@@ -298,6 +298,7 @@ LibertyReader::defineVisitors()
   defineAttrVisitor("is_macro", &LibertyReader::visitIsMacro);
   defineAttrVisitor("is_memory", &LibertyReader::visitIsMemory);
   defineAttrVisitor("is_pad", &LibertyReader::visitIsPad);
+  defineAttrVisitor("is_clock_cell", &LibertyReader::visitIsClockCell);
   defineAttrVisitor("is_level_shifter", &LibertyReader::visitIsLevelShifter);
   defineAttrVisitor("level_shifter_type", &LibertyReader::visitLevelShifterType);
   defineAttrVisitor("is_isolation_cell", &LibertyReader::visitIsIsolationCell);
@@ -2819,6 +2820,17 @@ LibertyReader::visitIsPad(LibertyAttr *attr)
   }
 }
 
+void
+LibertyReader::visitIsClockCell(LibertyAttr *attr)
+{
+  if (cell_) {
+    bool is_clock_cell, exists;
+    getAttrBool(attr, is_clock_cell, exists);
+    if (exists)
+      cell_->setIsClockCell(is_clock_cell);
+  }
+}
+
 void
 LibertyReader::visitIsLevelShifter(LibertyAttr *attr)
 {
diff --git a/liberty/LibertyReaderPvt.hh b/liberty/LibertyReaderPvt.hh
index f99fa1f1..6c7ea2d1 100644
--- a/liberty/LibertyReaderPvt.hh
+++ b/liberty/LibertyReaderPvt.hh
@@ -188,6 +188,7 @@ public:
   virtual void visitIsMacro(LibertyAttr *attr);
   virtual void visitIsMemory(LibertyAttr *attr);
   virtual void visitIsPad(LibertyAttr *attr);
+  virtual void visitIsClockCell(LibertyAttr *attr);
   virtual void visitIsLevelShifter(LibertyAttr *attr);
   virtual void visitLevelShifterType(LibertyAttr *attr);
   virtual void visitIsIsolationCell(LibertyAttr *attr);