diff --git a/mysql-test/suite/innodb_fts/r/bug87518.result b/mysql-test/suite/innodb_fts/r/bug87518.result
new file mode 100644
index 0000000..7b1872b
--- /dev/null
+++ b/mysql-test/suite/innodb_fts/r/bug87518.result
@@ -0,0 +1,23 @@
+#
+# Bug 87518: Server asserts when using n-gram full text searching with LIMIT
+#
+CREATE TABLE t1 (
+FTS_DOC_ID BIGINT UNSIGNED NOT NULL PRIMARY KEY,
+contents TEXT COLLATE utf8mb4_bin,
+FULLTEXT KEY fx_contents (contents) WITH PARSER ngram
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
+INSERT INTO t1 VALUES (1, 'xyz mnt'), (2, 'xyz mnt'), (3, 'xyz');
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz' IN BOOLEAN MODE);
+FTS_DOC_ID	contents
+1	xyz mnt
+2	xyz mnt
+3	xyz
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz' IN BOOLEAN MODE) LIMIT 1;
+FTS_DOC_ID	contents
+1	xyz mnt
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz mnt' IN BOOLEAN MODE) LIMIT 5;
+FTS_DOC_ID	contents
+1	xyz mnt
+2	xyz mnt
+3	xyz
+DROP TABLE t1;
diff --git a/mysql-test/suite/innodb_fts/r/limit_union.result b/mysql-test/suite/innodb_fts/r/limit_union.result
index 13fff0b..a0c6805 100644
--- a/mysql-test/suite/innodb_fts/r/limit_union.result
+++ b/mysql-test/suite/innodb_fts/r/limit_union.result
@@ -32,7 +32,7 @@ SELECT * FROM articles
 WHERE MATCH (title,body)
 AGAINST ('MySQL' IN BOOLEAN MODE) limit 1;
 id	title	body
-1	MySQL Tutorial	DBMS stands for DataBase ...
+6	MySQL Security	When configured properly, MySQL ...
 # Without optimization
 SET DEBUG = '+d,fts_union_limit_off';
 SELECT * FROM articles
diff --git a/mysql-test/suite/innodb_fts/t/bug87518.test b/mysql-test/suite/innodb_fts/t/bug87518.test
new file mode 100644
index 0000000..c3041be
--- /dev/null
+++ b/mysql-test/suite/innodb_fts/t/bug87518.test
@@ -0,0 +1,24 @@
+--source include/have_innodb.inc
+
+--echo #
+--echo # Bug 87518: Server asserts when using n-gram full text searching with LIMIT
+--echo #
+
+CREATE TABLE t1 (
+       FTS_DOC_ID BIGINT UNSIGNED NOT NULL PRIMARY KEY,
+       contents TEXT COLLATE utf8mb4_bin,
+       FULLTEXT KEY fx_contents (contents) WITH PARSER ngram
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
+
+INSERT INTO t1 VALUES (1, 'xyz mnt'), (2, 'xyz mnt'), (3, 'xyz');
+
+# The query completes with or without bug
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz' IN BOOLEAN MODE);
+
+# The query returns wrong result set with the bug
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz' IN BOOLEAN MODE) LIMIT 1;
+
+# The query crashes with the bug
+SELECT * FROM t1 WHERE MATCH(contents) AGAINST ('xyz mnt' IN BOOLEAN MODE) LIMIT 5;
+
+DROP TABLE t1;
diff --git a/storage/innobase/fts/fts0que.cc b/storage/innobase/fts/fts0que.cc
index 79d1f15..8916cae 100644
--- a/storage/innobase/fts/fts0que.cc
+++ b/storage/innobase/fts/fts0que.cc
@@ -746,6 +746,9 @@ fts_query_union_doc_id(
 
 		query->total_size += SIZEOF_RBT_NODE_ADD
 			+ sizeof(fts_ranking_t) + RANKING_WORDS_INIT_LEN;
+
+		if (query->limit != ULONG_UNDEFINED)
+			query->n_docs++;
 	}
 }
 
@@ -772,6 +775,9 @@ fts_query_remove_doc_id(
 		      SIZEOF_RBT_NODE_ADD + sizeof(fts_ranking_t));
 		query->total_size -= SIZEOF_RBT_NODE_ADD
 			+ sizeof(fts_ranking_t);
+
+		if (query->limit != ULONG_UNDEFINED)
+			query->n_docs--;
 	}
 }
 
@@ -892,6 +898,9 @@ fts_query_intersect_doc_id(
 
 			query->total_size += SIZEOF_RBT_NODE_ADD
 				+ sizeof(fts_ranking_t);
+
+			if (query->limit != ULONG_UNDEFINED)
+				query->n_docs++;
 		}
 	}
 }
@@ -3217,6 +3226,7 @@ fts_query_filter_doc_ids(
 
 	if (query->limit != ULONG_UNDEFINED
 	    && query->n_docs >= query->limit) {
+		ut_ad(0);
 		return(DB_SUCCESS);
 	}
 
@@ -3307,17 +3317,11 @@ fts_query_filter_doc_ids(
 			/* Add the word to the document's matched RB tree. */
 			fts_query_add_word_to_document(query, doc_id, word);
 		}
-
-		if (query->limit != ULONG_UNDEFINED
-		    && query->limit <= ++query->n_docs) {
-			goto func_exit;
-		}
 	}
 
 	/* Some sanity checks. */
 	ut_a(doc_id == node->last_doc_id);
 
-func_exit:
 	if (query->total_size > fts_result_cache_limit) {
 		return(DB_FTS_EXCEED_RESULT_CACHE_LIMIT);
 	} else {