diff --git a/src/MANYBODY/pair_polymorphic.h b/src/MANYBODY/pair_polymorphic.h
index 9917bcd96d..18eab46365 100644
--- a/src/MANYBODY/pair_polymorphic.h
+++ b/src/MANYBODY/pair_polymorphic.h
@@ -21,6 +21,7 @@ PairStyle(polymorphic,PairPolymorphic)
 #define LMP_PAIR_POLYMORPHIC_H
 
 #include "pair.h"
+#include <math.h>
 
 namespace LAMMPS_NS {
 
diff --git a/src/MANYBODY/pair_tersoff_mod.h b/src/MANYBODY/pair_tersoff_mod.h
index 8bc7ed37a8..fea3919be3 100644
--- a/src/MANYBODY/pair_tersoff_mod.h
+++ b/src/MANYBODY/pair_tersoff_mod.h
@@ -21,6 +21,7 @@ PairStyle(tersoff/mod,PairTersoffMOD)
 #define LMP_PAIR_TERSOFF_MOD_H
 
 #include "pair_tersoff.h"
+#include <math.h>
 
 namespace LAMMPS_NS {