diff --git a/constraint_solver/constraint_solver.h b/constraint_solver/constraint_solver.h
index 9132c37cd3..9381ed5e47 100644
--- a/constraint_solver/constraint_solver.h
+++ b/constraint_solver/constraint_solver.h
@@ -402,7 +402,8 @@ class Solver {
     STARTS_AFTER_END,
     STARTS_AFTER_START,
     STARTS_AT_END,
-    STARTS_AT_START
+    STARTS_AT_START,
+    STAYS_IN_SYNC
   };
 
   enum UnaryIntervalRelation {
diff --git a/constraint_solver/constraint_solver.swig b/constraint_solver/constraint_solver.swig
index 5d7b6373bf..6bb2f0950f 100644
--- a/constraint_solver/constraint_solver.swig
+++ b/constraint_solver/constraint_solver.swig
@@ -808,6 +808,12 @@ namespace operations_research {
                                                    operations_research::Solver::STARTS_AT_START,
                                                    other);
   }
+  Constraint* StaysInSync(IntervalVar* other) {
+    return self->solver()->MakeIntervalVarRelation(self,
+                                                   operations_research::Solver::STAYS_IN_SYNC,
+                                                   other);
+  }
+
 }
 
 %extend Sequence {
diff --git a/constraint_solver/timetabling.cc b/constraint_solver/timetabling.cc
index ce942841d4..788492143c 100644
--- a/constraint_solver/timetabling.cc
+++ b/constraint_solver/timetabling.cc
@@ -41,7 +41,8 @@ const char* kBinaryNames[] = {
   "STARTS_AFTER_END",
   "STARTS_AFTER_START",
   "STARTS_AT_END",
-  "STARTS_AT_START"
+  "STARTS_AT_START",
+  "STAYS_IN_SYNC"
 };
 }  // namespace
 
@@ -238,6 +239,16 @@ void IntervalBinaryRelation::InitialPropagate() {
         t2_->SetStartRange(t1_->StartMin(), t1_->StartMax());
       }
       break;
+    case Solver::STAYS_IN_SYNC:
+      if (t2_->MustBePerformed() && t1_->MayBePerformed()) {
+        t1_->SetStartRange(t2_->StartMin(), t2_->StartMax());
+        t1_->SetEndRange(t2_->EndMin(), t2_->EndMax());
+      }
+      if (t1_->MustBePerformed() && t2_->MayBePerformed()) {
+        t2_->SetStartRange(t1_->StartMin(), t1_->StartMax());
+        t2_->SetEndRange(t1_->EndMin(), t1_->EndMax());
+      }
+      break;
   }
 }
 
diff --git a/python/simple_meeting.py b/python/simple_meeting.py
index 247defae29..0a03cc6493 100644
--- a/python/simple_meeting.py
+++ b/python/simple_meeting.py
@@ -146,12 +146,10 @@ def main(unused_argv):
 
   # All copies are in sync with the original meeting.
   for p in all_people:
-    solver.Add(meeting.StartsAtStart(people_meeting_copies[p]))
-    solver.Add(meeting.EndsAtEnd(people_meeting_copies[p]))
+    solver.Add(meeting.StaysInSync(people_meeting_copies[p]))
 
   for r in all_rooms:
-    solver.Add(meeting.StartsAtStart(room_meeting_copies[r]))
-    solver.Add(meeting.EndsAtEnd(room_meeting_copies[r]))
+    solver.Add(meeting.StaysInSync(room_meeting_copies[r]))
 
   # Synchronize persons_presence and meetings.
   for p in all_people: