diff --git a/cozy/main.py b/cozy/main.py
index 29bbef60..620b6385 100755
--- a/cozy/main.py
+++ b/cozy/main.py
@@ -10,6 +10,8 @@
 import datetime
 import pickle
 
+from multiprocessing import Value
+
 from cozy import parse
 from cozy import codegen
 from cozy import common
@@ -55,6 +57,8 @@ def run():
     args = parser.parse_args()
     opts.read(args)
 
+    improve_count = Value('i', 0)
+
     if args.resume:
         with common.open_maybe_stdin(args.file or "-", mode="rb") as f:
             ast = pickle.load(f)
@@ -138,7 +142,8 @@ def callback(impl):
         ast = synthesis.improve_implementation(
             ast,
             timeout           = datetime.timedelta(seconds=args.timeout),
-            progress_callback = callback)
+            progress_callback = callback,
+            improve_count=improve_count)
 
         if server is not None:
             server.join()
@@ -190,3 +195,5 @@ def callback(impl):
                 f.write("share_info = {}\n".format(repr(share_info)))
             print("Implementation was dumped to {}".format(save_failed_codegen_inputs.value))
         raise
+
+    print("Number of improvements done: {}".format(improve_count.value))
diff --git a/cozy/synthesis/core.py b/cozy/synthesis/core.py
index dab42c6b..16ae6818 100644
--- a/cozy/synthesis/core.py
+++ b/cozy/synthesis/core.py
@@ -16,6 +16,8 @@
 import itertools
 from typing import Callable
 
+from multiprocessing import Value
+
 from cozy.syntax import (
     INT, BOOL, TMap,
     Op,
@@ -41,6 +43,8 @@
 from .acceleration import try_optimize
 from .enumeration import Enumerator, Fingerprint, retention_policy
 
+import threading
+
 eliminate_vars = Option("eliminate-vars", bool, False)
 enable_blacklist = Option("enable-blacklist", bool, False,
     description='If enabled, skip expressions that have been ' +
@@ -102,7 +106,8 @@ def improve(
         hints         : [Exp]              = (),
         examples      : [{str:object}]     = (),
         cost_model    : CostModel          = None,
-        ops           : [Op]               = ()):
+        ops           : [Op]               = (),
+        improve_count   : Value              = None):
     """Improve the target expression using enumerative synthesis.
 
     This function is a generator that yields increasingly better and better
@@ -271,6 +276,10 @@ def improve(
                 print("Now watching {} targets".format(len(watched_targets)))
                 break
 
+        if improve_count is not None:
+            with improve_count.get_lock():
+                improve_count.value += 1
+
 SearchInfo = namedtuple("SearchInfo", (
     "context",
     "targets",
diff --git a/cozy/synthesis/high_level_interface.py b/cozy/synthesis/high_level_interface.py
index 9e0444c8..1edb6a5b 100644
--- a/cozy/synthesis/high_level_interface.py
+++ b/cozy/synthesis/high_level_interface.py
@@ -11,6 +11,7 @@
 import sys
 import os
 from queue import Empty
+from multiprocessing import Value
 
 from cozy.common import typechecked, OrderedSet, LINE_BUFFER_MODE
 from cozy.syntax import Query, Op, Exp, EVar, EAll
@@ -43,7 +44,8 @@ def __init__(self,
             k,
             hints       : [Exp]     = [],
             freebies    : [Exp]     = [],
-            ops         : [Op]      = []):
+            ops         : [Op]      = [],
+            improve_count             = None):
         super().__init__()
         self.state = state
         self.assumptions = assumptions
@@ -55,6 +57,7 @@ def __init__(self,
         self.freebies = freebies
         self.ops = ops
         self.k = k
+        self.improve_count = improve_count
     def __str__(self):
         return "ImproveQueryJob[{}]".format(self.q.name)
     def run(self):
@@ -82,7 +85,8 @@ def run(self):
                         hints=self.hints,
                         stop_callback=lambda: self.stop_requested,
                         cost_model=cost_model,
-                        ops=self.ops)):
+                        ops=self.ops,
+                        improve_count=self.improve_count)):
 
                     new_rep, new_ret = unpack_representation(expr)
                     self.k(new_rep, new_ret)
@@ -94,7 +98,8 @@ def run(self):
 def improve_implementation(
         impl              : Implementation,
         timeout           : datetime.timedelta = datetime.timedelta(seconds=60),
-        progress_callback : Callable[[Implementation], Any] = None) -> Implementation:
+        progress_callback : Callable[[Implementation], Any] = None,
+        improve_count     : Value = None) -> Implementation:
     """Improve an implementation.
 
     This function tries to synthesize a better version of the given
@@ -142,7 +147,8 @@ def reconcile_jobs():
                         k=(lambda q: lambda new_rep, new_ret: solutions_q.put((q, new_rep, new_ret)))(q),
                         hints=[EStateVar(c).with_type(c.type) for c in impl.concretization_functions.values()],
                         freebies=[e for (v, e) in impl.concretization_functions.items() if EVar(v) in states_maintained_by_q],
-                        ops=impl.op_specs))
+                        ops=impl.op_specs,
+                        improve_count=improve_count))
 
             # figure out what old jobs we can stop
             impl_query_names = set(q.name for q in impl.query_specs)