diff --git a/src/e9patch/e9misc.cpp b/src/e9patch/e9misc.cpp
index 7e75559..2c3735c 100644
--- a/src/e9patch/e9misc.cpp
+++ b/src/e9patch/e9misc.cpp
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cerrno>
 #include <cstdlib>
 
 #include <sys/mman.h>