diff --git a/qfit/README.md b/qfit/README.md
index 9d08656..d8eec47 100644
--- a/qfit/README.md
+++ b/qfit/README.md
@@ -21,6 +21,10 @@ handles:
 - MIQP solvers are only listed in upstream's conda `environment.yml`,
   not in `install_requires` → `cvxopt` and `cplex` are pip-installed
   explicitly.
+- `logtools.py` imports `pkg_resources` at runtime but upstream never
+  declares setuptools (conda/virtualenv always shipped it, uv venvs
+  don't) — and setuptools ≥81 removed `pkg_resources` entirely →
+  `setuptools<81` is pip-installed explicitly.
 
 **CPLEX caveat**: the pip `cplex` wheel is the IBM Community Edition,
 limited to 1000 variables/constraints. Large residues/ligands may hit
diff --git a/qfit/build b/qfit/build
index 74616fe..22900c4 100755
--- a/qfit/build
+++ b/qfit/build
@@ -25,9 +25,12 @@ pbuild::install() {
     export CC=gcc
     export SETUPTOOLS_SCM_PRETEND_VERSION="${V_PKG}"
     # cplex is the IBM Community Edition pip wheel (problem-size limited);
-    # full CPLEX needs an academic license, see README
+    # full CPLEX needs an academic license, see README.
+    # setuptools<81: qfit's logtools.py imports pkg_resources at RUNTIME; uv venvs
+    # don't ship setuptools, and setuptools >=81 removed pkg_resources entirely
+    # (verified: the 84.0.0 wheel has zero pkg_resources files, 80.9.0 has them)
     "$UV" pip install --python "$PREFIX/venv/bin/python" \
-        cvxopt cplex "$SRC_DIR" || \
+        'setuptools<81' cvxopt cplex "$SRC_DIR" || \
         std::die 42 "qfit install failed - check build log above"
     [[ -x "$PREFIX/venv/bin/qfit_protein" ]] || std::die 42 "qfit_protein missing from venv"
 }