diff --git a/doc/build/changelog/unreleased_13/5645.rst b/doc/build/changelog/unreleased_13/5645.rst
new file mode 100644
index 0000000000..e1fe072632
--- /dev/null
+++ b/doc/build/changelog/unreleased_13/5645.rst
@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, postgresql
+    :tickets: 5645
+
+    For SQLAlchemy 1.3 only, setup.py pins pg8000 to a version lower than
+    1.16.6. Version 1.16.6 and above is supported by SQLAlchemy 1.4. Pull
+    request courtesy Giuseppe Lumia.
diff --git a/setup.py b/setup.py
index 891dcbf77c..1fdc91f120 100644
--- a/setup.py
+++ b/setup.py
@@ -192,7 +192,7 @@ def run_setup(with_cext):
             ],
             "postgresql": ["psycopg2"],
             "postgresql_psycopg2binary": ["psycopg2-binary"],
-            "postgresql_pg8000": ["pg8000"],
+            "postgresql_pg8000": ["pg8000<1.16.6"],
             "postgresql_psycopg2cffi": ["psycopg2cffi"],
             "oracle": ["cx_oracle"],
             "mssql_pyodbc": ["pyodbc"],