diff --git a/src/nox_poetry/core.py b/src/nox_poetry/core.py
index 4412737d..203eba44 100644
--- a/src/nox_poetry/core.py
+++ b/src/nox_poetry/core.py
@@ -3,9 +3,11 @@
 .. deprecated:: 0.8
    Use :func:`session` instead.
 """
+import warnings
 from pathlib import Path
 from typing import Any
 from typing import Iterable
+from typing import Optional
 
 import nox.sessions
 
@@ -16,12 +18,20 @@
 Session_install = nox.sessions.Session.install
 
 
+def _deprecate(name: str, replacement: Optional[str] = None) -> None:
+    message = f"nox_poetry.{name} is deprecated, use @nox_poetry.session instead"
+    if replacement is not None:
+        message += f" and invoke {replacement}"
+    warnings.warn(message, category=FutureWarning, stacklevel=2)
+
+
 def export_requirements(session: nox.sessions.Session) -> Path:
     """Export a requirements file from Poetry.
 
     .. deprecated:: 0.8
        Use :func:`session` instead.
     """  # noqa: D
+    _deprecate("export_requirements", "session.poetry.export_requirements")
     return Session(session).poetry.export_requirements()
 
 
@@ -33,6 +43,7 @@ def build_package(
     .. deprecated:: 0.8
        Use :func:`session` instead.
     """
+    _deprecate("build_package", "session.poetry.build_package")
     return Session(session).poetry.build_package(
         distribution_format=distribution_format
     )
@@ -44,6 +55,7 @@ def install(session: nox.sessions.Session, *args: str, **kwargs: Any) -> None:
     .. deprecated:: 0.8
        Use :func:`session` instead.
     """  # noqa: D
+    _deprecate("install", "session.install")
     Session(session).install(*args, **kwargs)
 
 
@@ -58,6 +70,7 @@ def installroot(
     .. deprecated:: 0.8
        Use :func:`session` instead.
     """
+    _deprecate("installroot", "session.poetry.installroot")
     Session(session).poetry.installroot(
         distribution_format=distribution_format, extras=extras
     )
@@ -86,4 +99,5 @@ def patch(
         distribution_format: The distribution format to use when the ``"."``
             argument is encountered in calls to ``session.install``.
     """
+    _deprecate("patch")
     nox.sessions.Session.install = install  # type: ignore[assignment]