diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 784def811..7652662d3 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -1657,7 +1657,7 @@ void EvalState::printStats()
         if (outPath != "-")
             fs.open(outPath, std::fstream::out);
         JSONObject topObj(outPath == "-" ? std::cerr : fs, true);
-        topObj.attr("cpuTime",cpuTime);
+        topObj.attr("cpuTime", cpuTime);
         {
             auto envs = topObj.object("envs");
             envs.attr("number", nrEnvs);
@@ -1700,6 +1700,13 @@ void EvalState::printStats()
         topObj.attr("nrLookups", nrLookups);
         topObj.attr("nrPrimOpCalls", nrPrimOpCalls);
         topObj.attr("nrFunctionCalls", nrFunctionCalls);
+        {
+            auto j = topObj.object("gc");
+            j.attr("heapSize", gc.getHeapSize());
+            j.attr("totalBytes", gc.allTimeWordsAllocated * WORD_SIZE);
+            j.attr("reclaimedBytes", gc.allTimeWordsFreed * WORD_SIZE);
+            j.attr("gcTime", gc.totalDurationMs / 1000.0);
+        }
 
         if (countCalls) {
             {
diff --git a/src/libexpr/gc.hh b/src/libexpr/gc.hh
index 6825329b5..7a87a4036 100644
--- a/src/libexpr/gc.hh
+++ b/src/libexpr/gc.hh
@@ -191,10 +191,16 @@ private:
 
     std::array<FreeList, 8> freeLists;
 
+public:
+
+    size_t getHeapSize() { return totalSize * WORD_SIZE; }
+
     size_t allTimeWordsAllocated = 0;
     size_t allTimeWordsFreed = 0;
     uint64_t totalDurationMs = 0;
 
+private:
+
     Object * allocObject(size_t size)
     {
         assert(size >= 2);