diff --git a/CMakeLists.txt b/CMakeLists.txt
index a18986278..00014e4c9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1388,6 +1388,7 @@ elseif(UNIX AND NOT APPLE AND NOT RISCOS AND NOT HAIKU)
       check_c_source_compiles("
           #include <linux/kd.h>
           #include <linux/keyboard.h>
+          #include <sys/ioctl.h>
           int main(int argc, char **argv) {
               struct kbentry kbe;
               kbe.kb_table = KG_CTRL;