diff --git a/src/cache.c b/src/cache.c
index 1b86ccd..420a009 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -105,6 +105,7 @@
 };
 
 struct cache_entry {
+	unsigned int complete;    /* An entry won't be valid until complete is not null. */
 	unsigned int latest_validation;     /* latest validation date */
 	unsigned int expire;      /* expiration date */
 	unsigned int age;         /* Origin server "Age" header value */
@@ -478,13 +479,9 @@
 
 		object = (struct cache_entry *)st->first_block->data;
 
-		/* does not need to test if the insertion worked, if it
-		 * doesn't, the blocks will be reused anyway */
-
 		shctx_lock(shctx);
-		if (eb32_insert(&cache->entries, &object->eb) != &object->eb) {
-			object->eb.key = 0;
-		}
+		/* The whole payload was cached, the entry can now be used. */
+		object->complete = 1;
 		/* remove from the hotlist */
 		shctx_row_dec_hot(shctx, st->first_block);
 		shctx_unlock(shctx);
@@ -700,7 +697,6 @@
 enum act_return http_action_store_cache(struct act_rule *rule, struct proxy *px,
 					struct session *sess, struct stream *s, int flags)
 {
-	unsigned int age;
 	long long hdr_age;
 	struct http_txn *txn = s->txn;
 	struct http_msg *msg = &txn->rsp;
@@ -716,10 +712,7 @@
 	struct http_hdr_ctx ctx;
 	size_t hdrs_len = 0;
 	int32_t pos;
-	unsigned int etag_length = 0;
-	unsigned int etag_offset = 0;
 	struct ist header_name = IST_NULL;
-	time_t last_modified = 0;
 	unsigned int vary_signature = 0;
 
 	/* Don't cache if the response came from a cache */
@@ -771,6 +764,8 @@
 	if (cache->vary_processing_enabled) {
 		if (!http_check_vary_header(htx, &vary_signature))
 			goto out;
+		if (vary_signature)
+			http_request_reduce_secondary_key(vary_signature, txn->cache_secondary_hash);
 	}
 	else if (http_find_header(htx, ist("Vary"), &ctx, 0)) {
 		goto out;
@@ -780,21 +775,72 @@
 
 	if (!(txn->flags & TX_CACHEABLE) || !(txn->flags & TX_CACHE_COOK) || (txn->flags & TX_CACHE_IGNORE))
 		goto out;
+
+	shctx_lock(shctx);
+	old = entry_exist(cache, txn->cache_hash);
+	if (old) {
+		if (vary_signature)
+			old = secondary_entry_exist(cconf->c.cache, old,
+						    txn->cache_secondary_hash);
+		if (old) {
+			if (!old->complete) {
+				/* An entry with the same primary key is already being
+				 * created, we should not try to store the current
+				 * response because it will waste space in the cache. */
+				shctx_unlock(shctx);
+				goto out;
+			}
+			eb32_delete(&old->eb);
+			old->eb.key = 0;
+		}
+	}
+	first = shctx_row_reserve_hot(shctx, NULL, sizeof(struct cache_entry));
+	if (!first) {
+		shctx_unlock(shctx);
+		goto out;
+	}
+	/* the received memory is not initialized, we need at least to mark
+	 * the object as not indexed yet.
+	 */
+	object = (struct cache_entry *)first->data;
+	memset(object, 0, sizeof(*object));
+	object->eb.key = key;
+	object->secondary_key_signature = vary_signature;
+	/* We need to temporarily set a valid expiring time until the actual one
+	 * is set by the end of this function (in case of concurrent accesses to
+	 * the same resource). This way the second access will find an existing
+	 * but not yet usable entry in the tree and will avoid storing its data. */
+	object->expire = now.tv_sec + 2;
+
+	memcpy(object->hash, txn->cache_hash, sizeof(object->hash));
+	if (vary_signature)
+		memcpy(object->secondary_key, txn->cache_secondary_hash, HTTP_CACHE_SEC_KEY_LEN);
+
+	/* Insert the entry in the tree even if the payload is not cached yet. */
+	if (eb32_insert(&cache->entries, &object->eb) != &object->eb) {
+		object->eb.key = 0;
+		shctx_unlock(shctx);
+		goto out;
+	}
+	shctx_unlock(shctx);
+
+	/* reserve space for the cache_entry structure */
+	first->len = sizeof(struct cache_entry);
+	first->last_append = NULL;
 
-	age = 0;
 	ctx.blk = NULL;
 	if (http_find_header(htx, ist("Age"), &ctx, 0)) {
 		if (!strl2llrc(ctx.value.ptr, ctx.value.len, &hdr_age) && hdr_age > 0) {
 			if (unlikely(hdr_age > CACHE_ENTRY_MAX_AGE))
 				hdr_age = CACHE_ENTRY_MAX_AGE;
-			age = hdr_age;
+			object->age = hdr_age;
 		}
 		http_remove_header(htx, &ctx);
 	}
 
 	/* Build a last-modified time that will be stored in the cache_entry and
 	 * compared to a future If-Modified-Since client header. */
-	last_modified = get_last_modified_time(htx);
+	object->last_modified = get_last_modified_time(htx);
 
 	chunk_reset(&trash);
 	for (pos = htx_get_first(htx); pos != -1; pos = htx_get_next(htx, pos)) {
@@ -813,8 +859,8 @@
 		if (type == HTX_BLK_HDR) {
 			header_name = htx_get_blk_name(htx, blk);
 			if (isteq(header_name, ist("etag"))) {
-				etag_length = sz - istlen(header_name);
-				etag_offset = sizeof(struct cache_entry) + b_data(&trash) - sz + istlen(header_name);
+				object->etag_length = sz - istlen(header_name);
+				object->etag_offset = sizeof(struct cache_entry) + b_data(&trash) - sz + istlen(header_name);
 			}
 		}
 		if (type == HTX_BLK_EOH)
@@ -826,36 +872,17 @@
 		goto out;
 
 	shctx_lock(shctx);
-	first = shctx_row_reserve_hot(shctx, NULL, sizeof(struct cache_entry) + trash.data);
-	if (!first) {
+	if (!shctx_row_reserve_hot(shctx, first, trash.data)) {
 		shctx_unlock(shctx);
 		goto out;
 	}
 	shctx_unlock(shctx);
 
-	/* the received memory is not initialized, we need at least to mark
-	 * the object as not indexed yet.
-	 */
-	object = (struct cache_entry *)first->data;
-	object->eb.node.leaf_p = NULL;
-	object->eb.key = 0;
-	object->age = age;
-	object->last_modified = last_modified;
-	object->secondary_key_signature = vary_signature;
-
-	/* reserve space for the cache_entry structure */
-	first->len = sizeof(struct cache_entry);
-	first->last_append = NULL;
 	/* cache the headers in a http action because it allows to chose what
 	 * to cache, for example you might want to cache a response before
 	 * modifying some HTTP headers, or on the contrary after modifying
 	 * those headers.
 	 */
-
-	/* Write the ETag information in the cache_entry if needed. */
-	object->etag_length = etag_length;
-	object->etag_offset = etag_offset;
-
 	/* does not need to be locked because it's in the "hot" list,
 	 * copy the headers */
 	if (shctx_row_data_append(shctx, first, NULL, (unsigned char *)trash.area, trash.data) < 0)
@@ -865,36 +892,10 @@
 	if (cache_ctx) {
 		cache_ctx->first_block = first;
 
-		object->eb.key = key;
-
-		memcpy(object->hash, txn->cache_hash, sizeof(object->hash));
-
-		/* Add the current request's secondary key to the buffer if needed. */
-		if (vary_signature) {
-			http_request_reduce_secondary_key(vary_signature, txn->cache_secondary_hash);
-			memcpy(object->secondary_key, txn->cache_secondary_hash, HTTP_CACHE_SEC_KEY_LEN);
-		}
-
-		/* Insert the node later on caching success */
-
-		shctx_lock(shctx);
-
-		old = entry_exist(cconf->c.cache, txn->cache_hash);
-		if (old) {
-			if (vary_signature)
-				old = secondary_entry_exist(cconf->c.cache, old,
-							    txn->cache_secondary_hash);
-
-			if (old) {
-				eb32_delete(&old->eb);
-				old->eb.key = 0;
-			}
-		}
-		shctx_unlock(shctx);
-
 		/* store latest value and expiration time */
 		object->latest_validation = now.tv_sec;
-		object->expire = now.tv_sec + http_calc_maxage(s, cconf->c.cache);
+		object->expire = now.tv_sec + http_calc_maxage(s, cache);
+
 		return ACT_RET_CONT;
 	}
 
@@ -903,6 +904,8 @@
 	if (first) {
 		shctx_lock(shctx);
 		first->len = 0;
+		if (object->eb.key)
+			eb32_delete(&object->eb);
 		object->eb.key = 0;
 		shctx_row_dec_hot(shctx, first);
 		shctx_unlock(shctx);
@@ -1453,7 +1456,8 @@
 
 	shctx_lock(shctx_ptr(cache));
 	res = entry_exist(cache, s->txn->cache_hash);
-	if (res) {
+	/* We must not use an entry that is not complete. */
+	if (res && res->complete) {
 		struct appctx *appctx;
 		entry_block = block_ptr(res);
 		shctx_row_inc_hot(shctx_ptr(cache), entry_block);