diff --git a/src/obfs_http.c b/src/obfs_http.c
index d2f31fac..adb03c45 100644
--- a/src/obfs_http.c
+++ b/src/obfs_http.c
@@ -67,7 +67,7 @@ static obfs_para_t obfs_http_st = {
     .is_enable       = &is_enable_http
 };
 
-obfs_para_t *const obfs_http = &obfs_http_st;
+obfs_para_t *obfs_http = &obfs_http_st;
 
 static int
 obfs_http_request(buffer_t *buf, size_t cap, obfs_t *obfs)
diff --git a/src/obfs_http.h b/src/obfs_http.h
index d80f939d..97725862 100644
--- a/src/obfs_http.h
+++ b/src/obfs_http.h
@@ -25,6 +25,6 @@
 
 #include "obfs.h"
 
-obfs_para_t *const obfs_http;
+extern obfs_para_t *obfs_http;
 
 #endif
diff --git a/src/obfs_tls.c b/src/obfs_tls.c
index 1c882c5c..0b3c27e0 100644
--- a/src/obfs_tls.c
+++ b/src/obfs_tls.c
@@ -180,7 +180,7 @@ static obfs_para_t obfs_tls_st = {
     .is_enable       = &is_enable_tls
 };
 
-obfs_para_t *const obfs_tls = &obfs_tls_st;
+obfs_para_t *obfs_tls = &obfs_tls_st;
 
 static int
 obfs_app_data(buffer_t *buf, size_t cap, obfs_t *obfs)
diff --git a/src/obfs_tls.h b/src/obfs_tls.h
index ad78f17f..9f12017e 100644
--- a/src/obfs_tls.h
+++ b/src/obfs_tls.h
@@ -140,6 +140,6 @@ typedef struct frame {
 
 #pragma pack(pop)
 
-obfs_para_t *const obfs_tls;
+extern obfs_para_t *obfs_tls;
 
 #endif