diff --git a/packages/docs-mcp/tests/__init__.py b/packages/docs-mcp/tests/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/packages/tapps-core/tests/__init__.py b/packages/tapps-core/tests/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/packages/tapps-mcp/tests/__init__.py b/packages/tapps-mcp/tests/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/pyproject.toml b/pyproject.toml
index f953c143..0739818b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -187,6 +187,13 @@ testpaths = [
 # passed positionally (e.g. ``pytest packages/tapps-mcp``), which overrides
 # testpaths. Excluding src/ keeps that invocation hermetic.
 norecursedirs = ["src", ".venv", "*.egg", "build", "dist", "node_modules"]
+# TAP-4575: docs-mcp test modules import shared fixtures via ``from tests.helpers
+# import ...``. With the tests/__init__.py files removed (so the three packages'
+# identically named ``tests`` trees no longer collide under importlib), that
+# import resolves only if docs-mcp's package root is on the path and ``tests`` is
+# treated as a namespace package (consider_namespace_packages above). Only
+# docs-mcp ships tests/helpers.py, so this is unambiguous.
+pythonpath = ["packages/docs-mcp"]
 asyncio_mode = "auto"
 timeout = 60
 markers = [
@@ -195,7 +202,13 @@ markers = [
     "optional_deps: marks tests requiring optional dependencies (sentence-transformers, faiss-cpu, cohere)",
     "brain_contract: marks tests requiring a running tapps-brain HTTP server (3.18+)",
 ]
-addopts = "-v --tb=short -p randomly --randomly-seed=last"
+addopts = "-v --tb=short -p randomly --randomly-seed=last --import-mode=importlib"
+# TAP-4575: importlib import mode lets the three packages' identically named
+# ``tests`` trees (each ships tests/__init__.py) be collected together from the
+# repo root without pytest's rootdir-based ImportPathMismatchError. Namespace
+# packages must be considered so docs-mcp's ``from tests.helpers import ...``
+# still resolves under importlib mode.
+consider_namespace_packages = true
 filterwarnings = [
     "ignore:tapps_core\\.memory is deprecated:DeprecationWarning",
     "ignore:tapps_core\\.memory\\.gc is deprecated:DeprecationWarning",
diff --git a/scripts/prepush-smoke.sh b/scripts/prepush-smoke.sh
index 64a78b26..4d6fd2dc 100755
--- a/scripts/prepush-smoke.sh
+++ b/scripts/prepush-smoke.sh
@@ -5,8 +5,10 @@
 # Intentionally avoids pytest-xdist (-n auto): parallel runs starve live Cursor
 # MCP child processes during push and can flake unrelated integration tests.
 #
-# Each test path runs in its own pytest invocation to avoid conftest.py
-# ImportPathMismatchError across packages.
+# Each curated test path runs in its own serial pytest invocation for that
+# xdist-avoidance reason. (The cross-package conftest.py ImportPathMismatchError
+# that once forced separate invocations is fixed — TAP-4575 added
+# --import-mode=importlib so a single root run collects all three packages.)
 
 set -euo pipefail
 
diff --git a/scripts/run-regression.sh b/scripts/run-regression.sh
index 87cad326..3a54ac69 100755
--- a/scripts/run-regression.sh
+++ b/scripts/run-regression.sh
@@ -15,17 +15,12 @@ if [[ "${1:-}" == "--serial" ]]; then
   XDIST=()
 fi
 
-echo "[regression] Full non-slow suite (all packages). Not part of git push." >&2
-FAILED=0
-for PKG in packages/tapps-mcp packages/tapps-core packages/docs-mcp; do
-  echo "[regression] $PKG/tests/" >&2
-  if ! uv run pytest "$PKG/tests/" -m "not slow" -q --tb=line --timeout=60 "${XDIST[@]}" --maxfail=3; then
-    FAILED=1
-  fi
-done
-
-if [[ "$FAILED" -ne 0 ]]; then
-  echo "[regression] FAILED — investigate with: uv run pytest <pkg>/tests/ -m 'not slow' -v" >&2
+echo "[regression] Full non-slow suite (all packages, single invocation). Not part of git push." >&2
+# TAP-4575: the three packages' tests are collected in one root pytest run
+# (testpaths + --import-mode=importlib in pyproject.toml). No more per-package
+# loop — a single invocation restores cross-package xdist parallelism.
+if ! uv run pytest -m "not slow" -q --tb=line --timeout=60 "${XDIST[@]}" --maxfail=3; then
+  echo "[regression] FAILED — investigate with: uv run pytest -m 'not slow' -v" >&2
   exit 1
 fi