diff --git a/src/Silisizer.cpp b/src/Silisizer.cpp
index f8393fc..eeef88f 100644
--- a/src/Silisizer.cpp
+++ b/src/Silisizer.cpp
@@ -20,6 +20,7 @@
 #include <fstream>
 #include <iostream>
 #include <list>
+#include <memory>
 
 #include "sta/Liberty.hh"
 #include "sta/Network.hh"
@@ -284,4 +285,49 @@ int Silisizer::silisize(const char *workdir) {
   return 0;
 }
 
+// Remove escape characters from JSON output
+static std::string jsonName(const char *s) {
+  std::string out;
+  for (; *s; ++s) if (*s != '\\') out.push_back(*s);
+  return out;
+}
+
+// JSON dumper for clock gating related instances
+void dumpIcgJson(const char *path) {
+  sta::Sta *sta = sta::Sta::sta();
+  sta::Network *network = sta->network();
+
+  std::ofstream f(path);
+  if (!f.good()) {
+    std::cerr << "dump_icg_json: cannot open " << path << " for write" << std::endl;
+    return;
+  }
+
+  // Dump gated registers.
+  f << "{\n  \"gated_flops\": [";
+  bool first = true;
+  for (const sta::Instance *reg : sta->clockGatedRegisters()) {
+    if (!first) f << ",";
+    f << "\n    \"" << jsonName(network->pathName(reg)) << "\"";
+    first = false;
+  }
+  f << (first ? "" : "\n  ") << "],\n  \"icgs\": {";
+
+  // Dump clock-gating instances mapped to their liberty cell names.
+  first = true;
+  std::unique_ptr<sta::LeafInstanceIterator> it(network->leafInstanceIterator());
+  while (it->hasNext()) {
+    sta::Instance *inst = it->next();
+    sta::Cell *cell = network->cell(inst);
+    if (!cell) continue;
+    sta::LibertyCell *lc = network->libertyCell(cell);
+    if (!lc || !lc->isClockGate()) continue;
+    if (!first) f << ",";
+    f << "\n    \"" << jsonName(network->pathName(inst))
+      << "\": \"" << jsonName(lc->name()) << "\"";
+    first = false;
+  }
+  f << (first ? "" : "\n  ") << "}\n}\n";
+}
+
 }  // namespace silisizer
diff --git a/src/Silisizer.h b/src/Silisizer.h
index 7963f30..5b50ea1 100644
--- a/src/Silisizer.h
+++ b/src/Silisizer.h
@@ -24,4 +24,6 @@ class Silisizer : public sta::Sta {
   int silisize(const char *workdir);
 };
 
+void dumpIcgJson(const char *path);
+
 }  // namespace silisizer
diff --git a/src/Silisizer.i b/src/Silisizer.i
index 891ddc4..63231ce 100644
--- a/src/Silisizer.i
+++ b/src/Silisizer.i
@@ -19,6 +19,7 @@
 %inline %{
 
 extern int silisize(const char *workdir);
+extern void dump_icg_json(const char *path);
 
 extern void test_abrt();
 extern void test_segv();
diff --git a/src/main.cpp b/src/main.cpp
index 3524b77..7f08de8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -97,6 +97,10 @@ int silisize(const char *workdir) {
   return sizer->silisize(workdir);
 }
 
+void dump_icg_json(const char *path) {
+  silisizer::dumpIcgJson(path);
+}
+
 void segv_call_fn() {
   int a;
   a = 6;
diff --git a/third_party/OpenSTA b/third_party/OpenSTA
index 88863d4..d915202 160000
--- a/third_party/OpenSTA
+++ b/third_party/OpenSTA
@@ -1 +1 @@
-Subproject commit 88863d432663675731c3f17e35523b99f888efda
+Subproject commit d915202ee9719f5f9d8430a2e3299709f18a4ca6