diff --git a/src/core/assert.h b/src/core/assert.h
index 928a3b76a..e97fa8aa6 100644
--- a/src/core/assert.h
+++ b/src/core/assert.h
@@ -65,7 +65,7 @@ void AssertBreakpoint (void);
     {                                                           \
       if (!(condition))                                         \
         {                                                       \
-          std::cout << "assert failed. file=" << __FILE__ <<    \
+          std::cerr << "assert failed. file=" << __FILE__ <<    \
             ", line=" << __LINE__ << ", cond=\""#condition <<   \
             "\"" << std::endl;                                  \
           ns3::AssertBreakpoint ();                             \
@@ -88,7 +88,7 @@ void AssertBreakpoint (void);
     {                                           \
       if (!(condition))                         \
         {                                       \
-          std::cout << message << std::endl;    \
+          std::cerr << message << std::endl;    \
           ns3::AssertBreakpoint ();             \
         }                                       \
     }                                           \
diff --git a/src/core/debug.h b/src/core/debug.h
index 0171387f2..3fc6fef4b 100644
--- a/src/core/debug.h
+++ b/src/core/debug.h
@@ -110,7 +110,7 @@ private:
     {                                           \
       if (g_debug.IsEnabled ())			\
         {                                       \
-          std::cout << msg << std::endl;        \
+          std::cerr << msg << std::endl;        \
         }                                       \
     }                                           \
   while (false)
@@ -125,7 +125,7 @@ private:
 #define NS_DEBUG_UNCOND(msg)         \
   do                                 \
     {                                \
-      std::cout << msg << std::endl; \
+      std::cerr << msg << std::endl; \
     }                                \
   while (false)
 
diff --git a/src/mobility/position.h b/src/mobility/position.h
index 884ba50b0..d34fadfb2 100644
--- a/src/mobility/position.h
+++ b/src/mobility/position.h
@@ -1,3 +1,4 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
 #ifndef POSITION_H
 #define POSITION_H
 
diff --git a/src/mobility/random-position.h b/src/mobility/random-position.h
index ee97a2286..8fcc54a6d 100644
--- a/src/mobility/random-position.h
+++ b/src/mobility/random-position.h
@@ -1,3 +1,4 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
 #ifndef RANDOM_POSITION_H
 #define RANDOM_POSITION_H
 
diff --git a/src/mobility/speed.h b/src/mobility/speed.h
index 5e2ad3c45..317fc4333 100644
--- a/src/mobility/speed.h
+++ b/src/mobility/speed.h
@@ -1,3 +1,4 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
 #ifndef SPEED_H
 #define SPEED_H
 
diff --git a/src/mobility/static-speed-helper.h b/src/mobility/static-speed-helper.h
index 0ba541b75..8737f2edd 100644
--- a/src/mobility/static-speed-helper.h
+++ b/src/mobility/static-speed-helper.h
@@ -1,3 +1,4 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
 #ifndef STATIC_SPEED_HELPER_H
 #define STATIC_SPEED_HELPER_H