diff --git a/dlls/wininet/http.c b/dlls/wininet/http.c
index 40f91fbbb39..fd58b1f3e16 100644
--- a/dlls/wininet/http.c
+++ b/dlls/wininet/http.c
@@ -381,7 +381,6 @@ static WCHAR *get_host_header( http_request_t *req )
 }
 
 struct data_stream_vtbl_t {
-    DWORD (*get_avail_data)(data_stream_t*,http_request_t*);
     BOOL (*end_of_data)(data_stream_t*,http_request_t*);
     DWORD (*read)(data_stream_t*,http_request_t*,BYTE*,DWORD,DWORD*,BOOL);
     BOOL (*drain_content)(data_stream_t*,http_request_t*);
@@ -440,12 +439,6 @@ typedef struct {
     BOOL end_of_data;
 } gzip_stream_t;
 
-static DWORD gzip_get_avail_data(data_stream_t *stream, http_request_t *req)
-{
-    /* Allow reading only from read buffer */
-    return 0;
-}
-
 static BOOL gzip_end_of_data(data_stream_t *stream, http_request_t *req)
 {
     gzip_stream_t *gzip_stream = (gzip_stream_t*)stream;
@@ -534,7 +527,6 @@ static void gzip_destroy(data_stream_t *stream)
 }
 
 static const data_stream_vtbl_t gzip_stream_vtbl = {
-    gzip_get_avail_data,
     gzip_end_of_data,
     gzip_read,
     gzip_drain_content,
@@ -2614,18 +2606,6 @@ static DWORD refill_read_buffer(http_request_t *req, BOOL allow_blocking, DWORD
     return res;
 }
 
-static DWORD netconn_get_avail_data(data_stream_t *stream, http_request_t *req)
-{
-    netconn_stream_t *netconn_stream = (netconn_stream_t*)stream;
-    DWORD avail = 0;
-
-    if(is_valid_netconn(req->netconn))
-        NETCON_query_data_available(req->netconn, &avail);
-    return netconn_stream->content_length == ~0u
-        ? avail
-        : min(avail, netconn_stream->content_length-netconn_stream->content_read);
-}
-
 static BOOL netconn_end_of_data(data_stream_t *stream, http_request_t *req)
 {
     netconn_stream_t *netconn_stream = (netconn_stream_t*)stream;
@@ -2682,7 +2662,6 @@ static void netconn_destroy(data_stream_t *stream)
 }
 
 static const data_stream_vtbl_t netconn_stream_vtbl = {
-    netconn_get_avail_data,
     netconn_end_of_data,
     netconn_read,
     netconn_drain_content,
@@ -2839,26 +2818,6 @@ static DWORD chunked_read(data_stream_t *stream, http_request_t *req, BYTE *buf,
     return ERROR_SUCCESS;
 }
 
-static DWORD chunked_get_avail_data(data_stream_t *stream, http_request_t *req)
-{
-    chunked_stream_t *chunked_stream = (chunked_stream_t*)stream;
-    DWORD avail = 0;
-
-    if(chunked_stream->state != CHUNKED_STREAM_STATE_READING_CHUNK) {
-        DWORD res, read;
-
-        /* try to process to the next chunk */
-        res = chunked_read(stream, req, NULL, 0, &read, FALSE);
-        if(res != ERROR_SUCCESS || chunked_stream->state != CHUNKED_STREAM_STATE_READING_CHUNK)
-            return 0;
-    }
-
-    if(is_valid_netconn(req->netconn) && chunked_stream->buf_size < chunked_stream->chunk_size)
-        NETCON_query_data_available(req->netconn, &avail);
-
-    return min(avail + chunked_stream->buf_size, chunked_stream->chunk_size);
-}
-
 static BOOL chunked_drain_content(data_stream_t *stream, http_request_t *req)
 {
     chunked_stream_t *chunked_stream = (chunked_stream_t*)stream;
@@ -2872,7 +2831,6 @@ static void chunked_destroy(data_stream_t *stream)
 }
 
 static const data_stream_vtbl_t chunked_stream_vtbl = {
-    chunked_get_avail_data,
     chunked_end_of_data,
     chunked_read,
     chunked_drain_content,
diff --git a/dlls/wininet/internet.h b/dlls/wininet/internet.h
index 6a49bf124d5..4cd1856bd6f 100644
--- a/dlls/wininet/internet.h
+++ b/dlls/wininet/internet.h
@@ -454,7 +454,6 @@ DWORD NETCON_secure_connect(netconn_t*,server_t*) DECLSPEC_HIDDEN;
 DWORD NETCON_send(netconn_t *connection, const void *msg, size_t len, int flags,
 		int *sent /* out */) DECLSPEC_HIDDEN;
 DWORD NETCON_recv(netconn_t*,void*,size_t,BOOL,int*) DECLSPEC_HIDDEN;
-BOOL NETCON_query_data_available(netconn_t *connection, DWORD *available) DECLSPEC_HIDDEN;
 BOOL NETCON_is_alive(netconn_t*) DECLSPEC_HIDDEN;
 LPCVOID NETCON_GetCert(netconn_t *connection) DECLSPEC_HIDDEN;
 int NETCON_GetCipherStrength(netconn_t*) DECLSPEC_HIDDEN;
diff --git a/dlls/wininet/netconnection.c b/dlls/wininet/netconnection.c
index 63b84aa2271..bab046f5792 100644
--- a/dlls/wininet/netconnection.c
+++ b/dlls/wininet/netconnection.c
@@ -869,32 +869,6 @@ DWORD NETCON_recv(netconn_t *connection, void *buf, size_t len, BOOL blocking, i
     }
 }
 
-/******************************************************************************
- * NETCON_query_data_available
- * Returns the number of bytes of peeked data plus the number of bytes of
- * queued, but unread data.
- */
-BOOL NETCON_query_data_available(netconn_t *connection, DWORD *available)
-{
-    *available = 0;
-
-    if(!connection->secure)
-    {
-        ULONG unread;
-        int retval = ioctlsocket(connection->socket, FIONREAD, &unread);
-        if (!retval)
-        {
-            TRACE("%d bytes of queued, but unread data\n", unread);
-            *available += unread;
-        }
-    }
-    else
-    {
-        *available = connection->peek_len;
-    }
-    return TRUE;
-}
-
 BOOL NETCON_is_alive(netconn_t *netconn)
 {
     int len;