diff --git a/include/errno.h b/include/errno.h
index 9d6803383cac9d6f244a35de6b1e05c3808c9f3d..9e1e3202b79dcd9d024a52d76e8b5ed99cafe6ad 100644
--- a/include/errno.h
+++ b/include/errno.h
@@ -10,7 +10,7 @@ extern "C" {
 #ifdef __GNUC__
 __attribute__((const))
 #endif
-extern int *__errno_location(void);
+int *__errno_location(void);
 #define errno (*__errno_location())
 
 #ifdef __cplusplus
diff --git a/include/resolv.h b/include/resolv.h
index 3b77fc7bd954e048bdd2ffc5090fb63c976606ad..5bb0832e75d73a708e0f6317c8e1576169fc9fba 100644
--- a/include/resolv.h
+++ b/include/resolv.h
@@ -122,7 +122,7 @@ struct res_sym {
 #define RES_PRF_REPLY	0x00002000
 #define RES_PRF_INIT	0x00004000
 
-extern struct __res_state *__res_state(void);
+struct __res_state *__res_state(void);
 #define _res (*__res_state())
 
 struct rrec;
diff --git a/include/sys/file.h b/include/sys/file.h
index 8b2eb01acb38faac9322d045f2a9f7c87dc20628..adb9dd522cb36c396ce73e03fbe62726bba130cc 100644
--- a/include/sys/file.h
+++ b/include/sys/file.h
@@ -11,7 +11,7 @@ extern "C" {
 #define LOCK_NB	4
 #define LOCK_UN	8
 
-extern int flock(int, int);
+int flock(int, int);
 
 #endif