diff --git a/src/simulator/high-precision.cc b/src/simulator/high-precision.cc
index 28daf3e53..3a62391d7 100644
--- a/src/simulator/high-precision.cc
+++ b/src/simulator/high-precision.cc
@@ -20,9 +20,14 @@
  */
 #include "high-precision.h"
 
-#ifdef HIGH_PRECISION_I128
+#include <cmath>
+#include <cassert>
 
 
+namespace ns3 {
+
+#ifdef HIGH_PRECISION_I128
+
 HighPrecision::HighPrecision ()
   : m_high (0),
     m_low (0)
@@ -87,9 +92,6 @@ HighPrecision::Zero (void)
 
 #else /* HIGH_PRECISION_I128 */
 
-#include <cmath>
-#include <cassert>
-
 const double HighPrecision::MAX_64 = 18446744073709551615.0;
 
 HighPrecision::HighPrecision ()
@@ -156,3 +158,5 @@ HighPrecision::Zero (void)
 }
 
 #endif /* HIGH_PRECISION_I128 */
+
+}; /* namespace ns3 */
diff --git a/src/simulator/high-precision.h b/src/simulator/high-precision.h
index 5bf7b1ede..2a4b5788a 100644
--- a/src/simulator/high-precision.h
+++ b/src/simulator/high-precision.h
@@ -23,6 +23,8 @@
 
 #include <stdint.h>
 
+namespace ns3 {
+
 #ifdef HIGH_PRECISION_I128
 
 /**
@@ -86,6 +88,6 @@ private:
 
 #endif /* HIGH_PRECISION_I128 */
 
-
+}; /* namespace ns3 */
 
 #endif /* HIGH_PRECISION_H */