diff --git a/src/simulator/scheduler-heap.cc b/src/simulator/scheduler-heap.cc
index 89be02fcc..746691be8 100644
--- a/src/simulator/scheduler-heap.cc
+++ b/src/simulator/scheduler-heap.cc
@@ -37,6 +37,7 @@
 #include "event-impl.h"
 #include "ns3/assert.h"
 
+#include <string>
 #define noTRACE_HEAP 1
 
 #ifdef TRACE_HEAP
diff --git a/src/simulator/scheduler-list.cc b/src/simulator/scheduler-list.cc
index 81372d794..71eaa8337 100644
--- a/src/simulator/scheduler-list.cc
+++ b/src/simulator/scheduler-list.cc
@@ -23,6 +23,7 @@
 #include "scheduler-factory.h"
 #include "event-impl.h"
 #include <utility>
+#include <string>
 #include "ns3/assert.h"
 
 namespace ns3 {
diff --git a/src/simulator/scheduler-map.cc b/src/simulator/scheduler-map.cc
index e5111dd6a..75f1fccaa 100644
--- a/src/simulator/scheduler-map.cc
+++ b/src/simulator/scheduler-map.cc
@@ -24,6 +24,7 @@
 #include "scheduler-factory.h"
 #include "event-impl.h"
 #include "ns3/assert.h"
+#include <string>
 
 #define noTRACE_MAP 1