diff --git a/include/scsi/sg.h b/include/scsi/sg.h
index 934ae389671d..a9f3c6fc3f57 100644
--- a/include/scsi/sg.h
+++ b/include/scsi/sg.h
@@ -70,6 +70,9 @@ Major new features in SG 3.x driver (cf SG 2.x drivers)
  (for the lk 2.2 series).
 */
 
+#ifdef __KERNEL__
+extern int sg_big_buff; /* for sysctl */
+#endif
 
 /* New interface introduced in the 3.x SG drivers follows */
 
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 44e9492368fd..5290c437f151 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -61,6 +61,9 @@
 #include <asm/stacktrace.h>
 #include <asm/io.h>
 #endif
+#ifdef CONFIG_CHR_DEV_SG
+#include <scsi/sg.h>
+#endif
 
 
 #if defined(CONFIG_SYSCTL)
@@ -116,10 +119,6 @@ static int min_percpu_pagelist_fract = 8;
 
 static int ngroups_max = NGROUPS_MAX;
 
-#ifdef CONFIG_CHR_DEV_SG
-extern int sg_big_buff;
-#endif
-
 #ifdef CONFIG_SPARC
 #include <asm/system.h>
 #endif