diff --git a/src/sf_proto.c b/src/sf_proto.c
index 75e867c..28ca58e 100644
--- a/src/sf_proto.c
+++ b/src/sf_proto.c
@@ -304,18 +304,33 @@ int sf_recv_vary_response(ConnectionInfo *conn, SFResponseInfo *response,
         return EINVAL;
     }
 
-    if (response->header.body_len <= sizeof(buffer->fixed)) {
+    if (response->header.body_len <= buffer->alloc_size) {
         if (response->header.body_len == 0) {
             return 0;
         }
     } else {
+        int alloc_size;
+        char *buff;
+
+        if (buffer->alloc_size > 0) {
+            alloc_size = 2 * buffer->alloc_size;
+        } else {
+            alloc_size = 64 * 1024;
+        }
+        while (alloc_size < response->header.body_len) {
+            alloc_size *= 2;
+        }
+
+        buff = (char *)fc_malloc(alloc_size);
+        if (buff == NULL) {
+            return ENOMEM;
+        }
         if (buffer->buff != buffer->fixed && buffer->buff != NULL) {
             free(buffer->buff);
         }
-        buffer->buff = (char *)fc_malloc(response->header.body_len);
-        if (buffer->buff == NULL) {
-            return ENOMEM;
-        }
+
+        buffer->buff = buff;
+        buffer->alloc_size = alloc_size;
     }
 
     if ((result=tcprecvdata_nb_ex(conn->sock, buffer->buff, response->
diff --git a/src/sf_proto.h b/src/sf_proto.h
index d9588b2..eda1fc6 100644
--- a/src/sf_proto.h
+++ b/src/sf_proto.h
@@ -172,10 +172,17 @@ typedef const char *(*sf_get_cmd_caption_func)(const int cmd);
 typedef int (*sf_get_cmd_log_level_func)(const int cmd);
 
 typedef struct {
-    char fixed[64 * 1024];
+    int alloc_size;
+    int fixed_size;
+    char *fixed;
     char *buff;
 } SFProtoRecvBuffer;
 
+typedef struct {
+    char fixed[64 * 1024];
+    SFProtoRecvBuffer buffer;
+} SFProtoRBufferFixedWrapper;
+
 typedef struct {
     sf_get_cmd_caption_func get_cmd_caption;
     sf_get_cmd_log_level_func get_cmd_log_level;
@@ -342,9 +349,23 @@ int sf_recv_vary_response(ConnectionInfo *conn, SFResponseInfo *response,
         const int network_timeout, const unsigned char expect_cmd,
         SFProtoRecvBuffer *buffer, const int min_body_len);
 
-static inline void sf_init_recv_buffer(SFProtoRecvBuffer *buffer)
+static inline void sf_init_recv_buffer_by_wrapper(
+        SFProtoRBufferFixedWrapper *wrapper)
 {
-    buffer->buff = buffer->fixed;
+    wrapper->buffer.fixed_size = sizeof(wrapper->fixed);
+    wrapper->buffer.alloc_size = sizeof(wrapper->fixed);
+    wrapper->buffer.fixed = wrapper->fixed;
+    wrapper->buffer.buff = wrapper->fixed;
+}
+
+static inline int sf_init_recv_buffer(SFProtoRecvBuffer *buffer,
+        const int init_size)
+{
+    buffer->alloc_size = init_size;
+    buffer->fixed_size = 0;
+    buffer->fixed = NULL;
+    buffer->buff = (char *)fc_malloc(init_size);
+    return buffer->buff != NULL ? 0 : ENOMEM;
 }
 
 static inline void sf_free_recv_buffer(SFProtoRecvBuffer *buffer)
@@ -353,6 +374,7 @@ static inline void sf_free_recv_buffer(SFProtoRecvBuffer *buffer)
         if (buffer->buff != NULL) {
             free(buffer->buff);
         }
+        buffer->alloc_size = buffer->fixed_size;
         buffer->buff = buffer->fixed;
     }
 }