diff --git a/src/query-builder/InsertQueryBuilder.ts b/src/query-builder/InsertQueryBuilder.ts
index a1f3c0de2f..1aa5545de9 100644
--- a/src/query-builder/InsertQueryBuilder.ts
+++ b/src/query-builder/InsertQueryBuilder.ts
@@ -410,6 +410,13 @@ export class InsertQueryBuilder<Entity> extends QueryBuilder<Entity> {
 
         query += `INTO ${tableName}`
 
+        if (
+            this.alias !== this.getMainTableName() &&
+            this.connection.driver.options.type === "postgres"
+        ) {
+            query += ` AS "${this.alias}"`
+        }
+
         // add columns expression
         if (columnsExpression) {
             query += `(${columnsExpression})`
diff --git a/test/functional/query-builder/insert-on-conflict/query-builder-insert-on-conflict.ts b/test/functional/query-builder/insert-on-conflict/query-builder-insert-on-conflict.ts
index e445e05d7b..e06017fc53 100644
--- a/test/functional/query-builder/insert-on-conflict/query-builder-insert-on-conflict.ts
+++ b/test/functional/query-builder/insert-on-conflict/query-builder-insert-on-conflict.ts
@@ -82,6 +82,84 @@ describe("query builder > insertion > on conflict", () => {
             }),
         ))
 
+    it("should support alias in insert", () =>
+        Promise.all(
+            connections.map(async (connection) => {
+                if (connection.driver.options.type !== "postgres") return
+
+                const post1 = new Post()
+                post1.id = "post#1"
+                post1.title = "About post"
+                post1.date = new Date("06 Aug 2020 00:12:01 GMT")
+
+                const post2 = new Post()
+                post2.id = "post#2"
+                post2.title = "Again post"
+                post2.date = new Date("06 Aug 2020 00:12:02 GMT")
+
+                await connection
+                    .createQueryBuilder()
+                    .insert()
+                    .into(Post)
+                    .values([post1, post2])
+                    .orIgnore()
+                    .execute()
+
+                await connection.manager
+                    .find(Post, {
+                        order: {
+                            id: "ASC",
+                        },
+                    })
+                    .should.eventually.be.eql([
+                        {
+                            id: "post#1",
+                            title: "About post",
+                            date: new Date("06 Aug 2020 00:12:01 GMT"),
+                        },
+                        {
+                            id: "post#2",
+                            title: "Again post",
+                            date: new Date("06 Aug 2020 00:12:02 GMT"),
+                        },
+                    ])
+
+                post1.date = new Date("07 Aug 2020 00:12:03 GMT")
+
+                post2.title = "Edited post"
+                post2.date = new Date("07 Aug 2020 00:12:04 GMT")
+
+                await connection
+                    .createQueryBuilder(Post, "p")
+                    .insert()
+                    .values([post1, post2])
+                    .onConflict(
+                        `("id") DO UPDATE SET "title" = excluded.title, "date" = excluded.date WHERE p.title != excluded.title`,
+                    )
+                    .setParameter("title", post2.title)
+                    .execute()
+
+                await connection.manager
+                    .find(Post, {
+                        order: {
+                            id: "ASC",
+                        },
+                    })
+                    .should.eventually.be.eql([
+                        {
+                            id: "post#1",
+                            title: "About post",
+                            date: new Date("06 Aug 2020 00:12:01 GMT"),
+                        },
+                        {
+                            id: "post#2",
+                            title: "Edited post",
+                            date: new Date("07 Aug 2020 00:12:04 GMT"),
+                        },
+                    ])
+            }),
+        ))
+
     it("should perform insertion correctly using orIgnore", () =>
         Promise.all(
             connections.map(async (connection) => {