diff --git a/src/core/shmgraphicsbufferallocator.cpp b/src/core/shmgraphicsbufferallocator.cpp
index f01680316f..1c61be66f0 100644
--- a/src/core/shmgraphicsbufferallocator.cpp
+++ b/src/core/shmgraphicsbufferallocator.cpp
@@ -13,6 +13,7 @@
 
 #include <drm_fourcc.h>
 #include <fcntl.h>
+#include <unistd.h>
 #include <sys/mman.h>
 
 namespace KWin