diff --git a/src/MANYBODY/pair_polymorphic.h b/src/MANYBODY/pair_polymorphic.h
index 9917bcd96df565ec9ec5953fe5b135a5d50ac7e8..18eab4636578e3cbb6e254ad853a4dc055d7925a 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 8bc7ed37a8f7345f4665d589d957d95f2822a910..fea3919be315688871058e832596600a7a3a7d71 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 {