diff --git a/dcalc/ArcDelayCalc.cc b/dcalc/ArcDelayCalc.cc
index 37dadf19..d20ca928 100644
--- a/dcalc/ArcDelayCalc.cc
+++ b/dcalc/ArcDelayCalc.cc
@@ -24,6 +24,8 @@
 
 #include "ArcDelayCalc.hh"
 
+#include <cstdlib>
+
 #include "Units.hh"
 #include "Liberty.hh"
 #include "TimingArc.hh"
diff --git a/liberty/TableModel.cc b/liberty/TableModel.cc
index 7d847a79..b4a0b325 100644
--- a/liberty/TableModel.cc
+++ b/liberty/TableModel.cc
@@ -24,6 +24,7 @@
 
 #include "TableModel.hh"
 
+#include <cmath>
 #include <string>
 
 #include "Error.hh"