diff --git a/dcalc/FindRoot.cc b/dcalc/FindRoot.cc
index a6bdde60..78826d62 100644
--- a/dcalc/FindRoot.cc
+++ b/dcalc/FindRoot.cc
@@ -16,7 +16,7 @@
 
 #include "FindRoot.hh"
 
-#include <algorithm> // abs
+#include <cmath> // abs
 
 namespace sta {
 
diff --git a/util/StringUtil.cc b/util/StringUtil.cc
index bdde20e1..685ae389 100644
--- a/util/StringUtil.cc
+++ b/util/StringUtil.cc
@@ -19,6 +19,7 @@
 #include <limits>
 #include <cctype>
 #include <cstdio>
+#include <cstdlib> // exit
 #include <array>
 #include <algorithm>