diff --git a/libavutil/cpu.c b/libavutil/cpu.c
index 454326cf2c..2d402117d0 100644
--- a/libavutil/cpu.c
+++ b/libavutil/cpu.c
@@ -40,7 +40,7 @@
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #endif
-#if HAVE_SYSCONF
+#if HAVE_UNISTD_H
 #include <unistd.h>
 #endif