1 files changed, 2 insertions, 0 deletions
diff --git a/csrc/smith.h b/csrc/smith.h
index 04015ee..489c053 100644
--- a/csrc/smith.h
+++ b/csrc/smith.h
@@ -9,6 +9,8 @@
 #ifndef SMITH_H_
 #define SMITH_H_
 
+#include <unistd.h>
+
 char * mr_smith();
 
 #endif // SMITH_H_