diff --git a/docs/installation.rst b/docs/installation.rst
index fd5cb6809..3546f2739 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -180,7 +180,7 @@ following dependencies first:
 
   - Either pyfuse3_ (preferably, newer and maintained) or llfuse_ (older,
     unmaintained now). See also the BORG_FUSE_IMPL env variable.
-  - See setup.py about the version requirements.
+  - See pyproject.toml about the version requirements.
 
 If you have troubles finding the right package names, have a look at the
 distribution specific sections below or the Vagrantfile in the git repository,
diff --git a/src/borg/archiver.py b/src/borg/archiver.py
index 6096a651f..e670df0fd 100644
--- a/src/borg/archiver.py
+++ b/src/borg/archiver.py
@@ -5198,7 +5198,7 @@ class Archiver:
         self.prerun_checks(logger, is_serve)
         if not is_supported_msgpack():
             logger.error("You do not have a supported version of the msgpack python package installed. Terminating.")
-            logger.error("This should never happen as specific, supported versions are required by our setup.py.")
+            logger.error("This should never happen as specific, supported versions are required by our pyproject.toml.")
             logger.error("Do not contact borgbackup support about this.")
             raise Error("unsupported msgpack version")
         if is_slow_msgpack():
diff --git a/src/borg/helpers/msgpack.py b/src/borg/helpers/msgpack.py
index ee3f47685..84d738168 100644
--- a/src/borg/helpers/msgpack.py
+++ b/src/borg/helpers/msgpack.py
@@ -135,7 +135,7 @@ def is_slow_msgpack():
 
 
 def is_supported_msgpack():
-    # DO NOT CHANGE OR REMOVE! See also requirements and comments in setup.py.
+    # DO NOT CHANGE OR REMOVE! See also requirements and comments in pyproject.toml.
     import msgpack
     return (1, 0, 3) <= msgpack.version <= (1, 0, 7) and \
            msgpack.version not in []  # < add bad releases here to deny list