diff --git a/src/openvpn/socket.c b/src/openvpn/socket.c
index 211e7441..29de56fd 100644
--- a/src/openvpn/socket.c
+++ b/src/openvpn/socket.c
@@ -1491,6 +1491,22 @@ done:
     gc_free(&gc);
 }
 
+/*
+ * Stream buffer handling prototypes -- stream_buf is a helper class
+ * to assist in the packetization of stream transport protocols
+ * such as TCP.
+ */
+
+static void
+stream_buf_init(struct stream_buf *sb, struct buffer *buf,
+                const unsigned int sockflags, const int proto);
+
+static void
+stream_buf_close(struct stream_buf *sb);
+
+static bool
+stream_buf_added(struct stream_buf *sb, int length_added);
+
 /* For stream protocols, allocate a buffer to build up packet.
  * Called after frame has been finalized. */
 
@@ -2500,7 +2516,7 @@ stream_buf_reset(struct stream_buf *sb)
     sb->len = -1;
 }
 
-void
+static void
 stream_buf_init(struct stream_buf *sb,
                 struct buffer *buf,
                 const unsigned int sockflags,
@@ -2574,7 +2590,7 @@ stream_buf_read_setup_dowork(struct link_socket *sock)
     return !sock->stream_buf.residual_fully_formed;
 }
 
-bool
+static bool
 stream_buf_added(struct stream_buf *sb,
                  int length_added)
 {
@@ -2641,7 +2657,7 @@ stream_buf_added(struct stream_buf *sb,
     }
 }
 
-void
+static void
 stream_buf_close(struct stream_buf *sb)
 {
     free_buf(&sb->residual);
diff --git a/src/openvpn/socket.h b/src/openvpn/socket.h
index 479d1150..7329a518 100644
--- a/src/openvpn/socket.h
+++ b/src/openvpn/socket.h
@@ -994,21 +994,6 @@ link_socket_set_outgoing_addr(const struct buffer *buf,
     }
 }
 
-/*
- * Stream buffer handling -- stream_buf is a helper class
- * to assist in the packetization of stream transport protocols
- * such as TCP.
- */
-
-void stream_buf_init(struct stream_buf *sb,
-                     struct buffer *buf,
-                     const unsigned int sockflags,
-                     const int proto);
-
-void stream_buf_close(struct stream_buf *sb);
-
-bool stream_buf_added(struct stream_buf *sb, int length_added);
-
 static inline bool
 stream_buf_read_setup(struct link_socket *sock)
 {