diff --git a/lib/ecto/adapters/sqlite3/connection.ex b/lib/ecto/adapters/sqlite3/connection.ex
index b9d457b..969191b 100644
--- a/lib/ecto/adapters/sqlite3/connection.ex
+++ b/lib/ecto/adapters/sqlite3/connection.ex
@@ -748,6 +748,9 @@ defmodule Ecto.Adapters.SQLite3.Connection do
 
   defp conflict_target([]), do: ""
 
+  defp conflict_target({:unsafe_fragment, fragment}),
+    do: [fragment, ?\s]
+
   defp conflict_target(targets) do
     [?(, intersperse_map(targets, ?,, &quote_name/1), ?), ?\s]
   end
diff --git a/test/ecto/adapters/sqlite3/connection/insert_test.exs b/test/ecto/adapters/sqlite3/connection/insert_test.exs
index f95acca..166213f 100644
--- a/test/ecto/adapters/sqlite3/connection/insert_test.exs
+++ b/test/ecto/adapters/sqlite3/connection/insert_test.exs
@@ -60,6 +60,22 @@ defmodule Ecto.Adapters.SQLite3.Connection.InsertTest do
     assert query ==
              ~s{INSERT INTO "schema" AS s0 ("x","y") VALUES (?,?) ON CONFLICT ("x","y") DO UPDATE SET "z" = 'foo' RETURNING "z"}
 
+    # For :unsafe_fragment
+    update = from("schema", update: [set: [z: "foo"]]) |> plan(:update_all)
+
+    query =
+      insert(
+        nil,
+        "schema",
+        [:x, :y],
+        [[:x, :y]],
+        {update, [], {:unsafe_fragment, "foobar"}},
+        [:z]
+      )
+
+    assert query ==
+             ~s{INSERT INTO "schema" AS s0 ("x","y") VALUES (?,?) ON CONFLICT foobar DO UPDATE SET "z" = 'foo' RETURNING "z"}
+
     assert_raise ArgumentError, "Upsert in SQLite3 requires :conflict_target", fn ->
       conflict_target = []