diff --git a/src/speakup_soft.c b/src/speakup_soft.c
index 1eec529..507c4d7 100644
--- a/src/speakup_soft.c
+++ b/src/speakup_soft.c
@@ -24,6 +24,7 @@
 #include <linux/unistd.h>
 #include <linux/miscdevice.h> /* for misc_register, and SYNTH_MINOR */
 #include <linux/poll.h> /* for poll_wait() */
+#include <linux/sched.h>
 
 #include "spk_priv.h"
 #include "speakup.h"