diff --git a/layer/VkLayer_FROG_gamescope_wsi.cpp b/layer/VkLayer_FROG_gamescope_wsi.cpp
index ac91c8c..4bbec4f 100644
--- a/layer/VkLayer_FROG_gamescope_wsi.cpp
+++ b/layer/VkLayer_FROG_gamescope_wsi.cpp
@@ -15,6 +15,7 @@
 
 // For limiter file.
 #include <fcntl.h>
+#include <unistd.h>
 
 using namespace std::literals;