diff --git a/include/common/htx.h b/include/common/htx.h
index 003680a2b..ea7361cfc 100644
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -158,8 +158,7 @@ struct htx {
 	uint64_t extra;  /* known bytes amount remaining to receive */
 	uint32_t flags;  /* HTX_FL_* */
 
-	int32_t sl_off; /* Offset of the start-line of the HTTP message relatively to the beginning the
-			   data block. -1 if unset */
+	int32_t sl_pos; /* position of the start-line of the HTTP message. -1 if unset */
 
 	struct htx_blk blocks[0]; /* Blocks representing the HTTP message itself */
 };
@@ -273,17 +272,6 @@ static inline struct ist htx_sl_res_reason(const struct htx_sl *sl)
 	return htx_sl_p3(sl);
 }
 
-/* Returns the HTX start-line if set, otherwise it returns NULL. */
-static inline struct htx_sl *htx_get_stline(struct htx *htx)
-{
-	struct htx_sl *sl = NULL;
-
-	if (htx->used && htx->sl_off != -1)
-		sl = ((void *)htx->blocks + htx->sl_off);
-
-	return sl;
-}
-
 /* Returns the array index of a block given its position <pos> */
 static inline uint32_t htx_pos_to_idx(const struct htx *htx, uint32_t pos)
 {
@@ -611,6 +599,21 @@ static inline struct ist htx_get_blk_value(const struct htx *htx, const struct h
 	return ret;
 }
 
+/* Returns the HTX start-line if set, otherwise it returns NULL. */
+static inline struct htx_sl *htx_get_stline(struct htx *htx)
+{
+	struct htx_sl *sl = NULL;
+
+	if (htx->used && htx->sl_pos != -1) {
+		struct htx_blk *blk = htx_get_blk(htx, htx->sl_pos);
+
+		if (blk)
+			sl = htx_get_blk_ptr(htx, blk);
+	}
+	return sl;
+}
+
+
 /* Removes <n> bytes from the beginning of DATA block <blk>. The block's start
  * address and its length are adjusted, and the htx's total data count is
  * updated. This is used to mark that part of some data were transfered
@@ -677,7 +680,7 @@ static inline void htx_reset(struct htx *htx)
 	htx->data = htx->used = htx->tail = htx->head  = htx->front = 0;
 	htx->extra = 0;
 	htx->flags = HTX_FL_NONE;
-	htx->sl_off = -1;
+	htx->sl_pos = -1;
 }
 
 /* returns the available room for raw data in buffer <buf> once HTX overhead is
@@ -792,8 +795,8 @@ static inline void htx_dump(struct htx *htx)
 	fprintf(stderr, "htx:%p [ size=%u - data=%u - used=%u - wrap=%s - extra=%llu]\n",
 		htx, htx->size, htx->data, htx->used, (htx->tail >= htx->head) ? "NO" : "YES",
 		(unsigned long long)htx->extra);
-	fprintf(stderr, "\thead=%u, tail=%u - front=%u\n",
-		htx->head, htx->tail, htx->front);
+	fprintf(stderr, "\tsl_pos=%d - head=%u, tail=%u - front=%u\n",
+		htx->sl_pos, htx->head, htx->tail, htx->front);
 
 	for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) {
 		struct htx_sl     *sl;
diff --git a/src/cache.c b/src/cache.c
index 44355cd86..7402e5efd 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -915,7 +915,7 @@ static size_t htx_cache_dump_headers(struct appctx *appctx, struct htx *htx)
 
 		/* Set the start-line offset */
 		if (type == HTX_BLK_RES_SL)
-			htx->sl_off = blk->addr;
+			htx->sl_pos = htx_get_blk_pos(htx, blk);
 
 		/* Copy info and data */
 		blk->info = info;
diff --git a/src/http_htx.c b/src/http_htx.c
index 471f1ab81..e6332f7da 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -40,7 +40,7 @@ struct htx_sl *http_find_stline(struct htx *htx)
 
 		if (type == HTX_BLK_REQ_SL || type == HTX_BLK_RES_SL) {
 			sl = htx_get_blk_ptr(htx, blk);
-			htx->sl_off = blk->addr;
+			htx->sl_pos = pos;
 			break;
 		}
 
@@ -194,7 +194,7 @@ int http_replace_stline(struct htx *htx, const struct ist p1, const struct ist p
 		struct htx_blk *blk = htx_get_blk(htx, pos);
 		enum htx_blk_type type = htx_get_blk_type(blk);
 
-		if (htx->sl_off == blk->addr) {
+		if (htx->sl_pos == pos) {
 			if (!htx_replace_stline(htx, blk, p1, p2, p3))
 				return 0;
 			return 1;
diff --git a/src/htx.c b/src/htx.c
index 9f75f7afa..bdde868af 100644
--- a/src/htx.c
+++ b/src/htx.c
@@ -28,7 +28,7 @@ struct htx_blk *htx_defrag(struct htx *htx, struct htx_blk *blk)
 	struct htx_blk *newblk, *oldblk;
 	uint32_t new, old, blkpos;
 	uint32_t addr, blksz;
-	int32_t sl_off = -1;
+	int32_t sl_pos = -1;
 
 	if (!htx->used)
 		return NULL;
@@ -50,9 +50,9 @@ struct htx_blk *htx_defrag(struct htx *htx, struct htx_blk *blk)
 		newblk->info = oldblk->info;
 		blksz = htx_get_blksz(oldblk);
 
-		/* update the start-line offset */
-		if (htx->sl_off == oldblk->addr)
-			sl_off = addr;
+		/* update the start-line position */
+		if (htx->sl_pos == old)
+			sl_pos = new;
 
 		/* if <blk> is defined, set its new position */
 		if (blk != NULL && blk == oldblk)
@@ -65,7 +65,7 @@ struct htx_blk *htx_defrag(struct htx *htx, struct htx_blk *blk)
 	}
 
 	htx->used = new;
-	htx->sl_off = sl_off;
+	htx->sl_pos = sl_pos;
 	htx->head = 0;
 	htx->front = htx->tail = new - 1;
 	memcpy((void *)htx->blocks, (void *)tmp->blocks, htx->size);
@@ -215,12 +215,13 @@ struct htx_blk *htx_remove_blk(struct htx *htx, struct htx_blk *blk)
 	enum htx_blk_type type = htx_get_blk_type(blk);
 	uint32_t next, pos, wrap;
 
+	pos  = htx_get_blk_pos(htx, blk);
 	if (type != HTX_BLK_UNUSED) {
 		/* Mark the block as unused, decrement allocated size */
 		htx->data -= htx_get_blksz(blk);
 		blk->info = ((uint32_t)HTX_BLK_UNUSED << 28);
-		if (htx->sl_off == blk->addr)
-			htx->sl_off = -1;
+		if (htx->sl_pos == pos)
+			htx->sl_pos = -1;
 	}
 
 	/* This is the last block in use */
@@ -232,7 +233,6 @@ struct htx_blk *htx_remove_blk(struct htx *htx, struct htx_blk *blk)
 	}
 
 	/* There is at least 2 blocks, so tail is always >= 0 */
-	pos  = htx_get_blk_pos(htx, blk);
 	blk  = NULL;
 	next = pos + 1; /* By default retrun the next block */
 	wrap = htx_get_wrap(htx);
@@ -271,11 +271,11 @@ struct htx_blk *htx_remove_blk(struct htx *htx, struct htx_blk *blk)
 	}
 
 	blk = htx_get_blk(htx, next);
-	if (htx->sl_off == -1) {
-		/* Try to update the start-line offset, if possible */
+	if (htx->sl_pos == -1) {
+		/* Try to update the start-line payload addr, if possible */
 		type = htx_get_blk_type(blk);
 		if (type == HTX_BLK_REQ_SL || type == HTX_BLK_RES_SL)
-			htx->sl_off = blk->addr;
+			htx->sl_pos = htx_get_blk_pos(htx, blk);
 	}
   end:
 	if (pos == htx->front)
@@ -538,8 +538,8 @@ struct htx_ret htx_xfer_blks(struct htx *dst, struct htx *src, uint32_t count,
 			break;
 		}
 
-		if (dst->sl_off == -1 && src->sl_off == blk->addr)
-			dst->sl_off = dstblk->addr;
+		if (dst->sl_pos == -1 && src->sl_pos == htx_get_blk_pos(src, blk))
+			dst->sl_pos = htx_get_blk_pos(dst, dstblk);
 	  next:
 		blk = htx_remove_blk(src, blk);
 		if (type == mark)
@@ -612,9 +612,6 @@ struct htx_sl *htx_replace_stline(struct htx *htx, struct htx_blk *blk, const st
 	sl = htx_get_blk_ptr(htx, blk);
 	tmp.info = sl->info;
 	tmp.flags = sl->flags;
-	if (htx->sl_off == blk->addr)
-		htx->sl_off = -1;
-
 
 	size = sizeof(*sl) + p1.len + p2.len + p3.len;
 	delta = size - htx_get_blksz(blk);
@@ -642,8 +639,6 @@ struct htx_sl *htx_replace_stline(struct htx *htx, struct htx_blk *blk, const st
 	sl = htx_get_blk_ptr(htx, blk);
 	sl->info = tmp.info;
 	sl->flags = tmp.flags;
-	if (htx->sl_off == -1)
-		htx->sl_off = blk->addr;
 
 	HTX_SL_P1_LEN(sl) = p1.len;
 	HTX_SL_P2_LEN(sl) = p2.len;
@@ -678,8 +673,8 @@ struct htx_sl *htx_add_stline(struct htx *htx, enum htx_blk_type type, unsigned
 	blk->info += size;
 
 	sl = htx_get_blk_ptr(htx, blk);
-	if (htx->sl_off == -1)
-		htx->sl_off = blk->addr;
+	if (htx->sl_pos == -1)
+		htx->sl_pos = htx_get_blk_pos(htx, blk);
 
 	sl->flags = flags;