diff --git a/src/taalgos/emptinessta.cc b/src/taalgos/emptinessta.cc
index cf59352b0..190b4592b 100644
--- a/src/taalgos/emptinessta.cc
+++ b/src/taalgos/emptinessta.cc
@@ -28,7 +28,7 @@
 
 #include "emptinessta.hh"
 #include "misc/memusage.hh"
-#include <math.h>
+#include <cstdlib>
 #include "tgba/bddprint.hh"
 
 namespace spot