1 files changed, 1 insertions, 0 deletions

diff --git a/src/grid.h b/src/grid.h
index af92a71..572bc66 100644
--- a/src/grid.h
+++ b/src/grid.h
@@ -3,6 +3,7 @@
 
 #include <math.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <QHash>
 
 const double GRID_COARSE = 0.001;