diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index eda3308..833113c 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -4,6 +4,11 @@ name: Publish Python 🐍 distribution 📦 to PyPI and TestPyPI
 # yamllint disable-line rule:truthy
 on: push
 
+# For now always take the "reduced" form of the version, even for those
+# actions runs that do not push to a package index.
+env:
+  VERSIONINGIT_FOR_PACKAGE_INDEX: true
+
 jobs:
   build:
     name: Build distribution 📦
@@ -22,7 +27,7 @@ jobs:
       - name: Install pypa/build
         run: |
           python3 -m pip install -U pip setuptools
-          python3 -m pip install build --user
+          python3 -m pip install build
       - name: Build a binary wheel and a source tarball
         run: python3 -m build
       - name: Store the distribution packages
diff --git a/pyproject.toml b/pyproject.toml
index 7668046..6d76efa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -94,6 +94,12 @@ section-order = ["future", "standard-library", "attrs", "third-party", "chemistr
 "attrs" = ["attr"]
 "chemistry" = ["psi4", "pyscf"]
 
+[tool.versioningit.format]
+method = { module = "versioningit_override", value = "my_format", module-dir = "pyresponse" }
+
+[tool.versioningit.template-fields.version-tuple]
+pep440 = true
+
 [tool.versioningit.vcs]
 method = "git"
 match = ["v*"]
diff --git a/pyresponse/versioningit_override.py b/pyresponse/versioningit_override.py
new file mode 100644
index 0000000..35759cb
--- /dev/null
+++ b/pyresponse/versioningit_override.py
@@ -0,0 +1,35 @@
+from os import getenv
+from typing import Any, Dict
+
+from versioningit import VCSDescription
+from versioningit.basics import DEFAULT_FORMATS
+
+_ENVVARNAME = "VERSIONINGIT_FOR_PACKAGE_INDEX"
+
+
+def my_format(
+    *, description: VCSDescription, base_version: str, next_version: str, params: Dict[str, Any]
+) -> str:
+    state = description.state
+    assert state in {"distance", "dirty", "distance-dirty"}
+
+    if getenv(_ENVVARNAME, "False").lower() in ("true", "1", "t"):
+        fmt_distance = "{base_version}.post{distance}"
+        if state != "distance":
+            raise RuntimeError("dirty state doesn't make sense when building for a package index")
+    else:
+        # Default but missing {vcs} before {rev}
+        fmt_distance = "{base_version}.post{distance}+{rev}"
+        # Default
+        fmt_dirty = DEFAULT_FORMATS["dirty"]
+        # Default but missing {vcs} before {rev}
+        fmt_distance_dirty = "{base_version}.post{distance}+{rev}.d{build_date:%Y%m%d}"
+
+    if state == "distance":
+        fmt = fmt_distance
+    elif state == "dirty":
+        fmt = fmt_dirty
+    elif state == "distance-dirty":
+        fmt = fmt_distance_dirty
+
+    return fmt.format_map({**description.fields, "base_version": base_version})