diff --git a/ocrad-0.23-pre1/character_r11.cc b/ocrad-0.23-pre1/character_r11.cc
index 9b054e1..39d2362 100644
--- a/ocrad-0.23-pre1/character_r11.cc
+++ b/ocrad-0.23-pre1/character_r11.cc
@@ -20,6 +20,7 @@
 #include <cstdio>
 #include <vector>
 #include <stdint.h>
+#include <cstdlib>
 
 #include "common.h"
 #include "rectangle.h"
diff --git a/ocrad-0.23-pre1/configure b/ocrad-0.23-pre1/configure
index 706fd8c..e746edf 100755
--- a/ocrad-0.23-pre1/configure
+++ b/ocrad-0.23-pre1/configure
@@ -24,7 +24,7 @@ includedir='${prefix}/include'
 infodir='$(datarootdir)/info'
 libdir='${exec_prefix}/lib'
 mandir='$(datarootdir)/man'
-CXX=g++
+# CXX=g++
 CPPFLAGS=
 CXXFLAGS='-Wall -W -O2'
 LDFLAGS=
diff --git a/ocrad-0.23-pre1/feats_test0.cc b/ocrad-0.23-pre1/feats_test0.cc
index 48bb029..2223fc3 100644
--- a/ocrad-0.23-pre1/feats_test0.cc
+++ b/ocrad-0.23-pre1/feats_test0.cc
@@ -20,6 +20,7 @@
 #include <cstdio>
 #include <vector>
 #include <stdint.h>
+#include <cstdlib>
 
 #include "common.h"
 #include "rectangle.h"
diff --git a/ocrad-0.23-pre1/profile.cc b/ocrad-0.23-pre1/profile.cc
index d1d81e3..441c4a9 100644
--- a/ocrad-0.23-pre1/profile.cc
+++ b/ocrad-0.23-pre1/profile.cc
@@ -20,6 +20,7 @@
 #include <cstdio>
 #include <vector>
 #include <stdint.h>
+#include <cstdlib>
 
 #include "common.h"
 #include "rectangle.h"
diff --git a/ocrad-0.23-pre1/track.cc b/ocrad-0.23-pre1/track.cc
index 12e2c4a..31881be 100644
--- a/ocrad-0.23-pre1/track.cc
+++ b/ocrad-0.23-pre1/track.cc
@@ -19,6 +19,7 @@
 #include <algorithm>
 #include <cstdio>
 #include <vector>
+#include <cstdlib>
 
 #include "common.h"
 #include "rectangle.h"