diff --git a/macros.python b/macros.python
index 0d29ae0..0ba4d78 100644
--- a/macros.python
+++ b/macros.python
@@ -169,7 +169,7 @@ print(_python_macro_cache[cache_key][name])
   PYTHONPATH="${PYTHONPATH:-%{buildroot}%{python_sitearch}:%{buildroot}%{python_sitelib}}"\\\
   PYTHONDONTWRITEBYTECODE=1\\\
   %{?__pytest_addopts:PYTEST_ADDOPTS="${PYTEST_ADDOPTS:-} %{__pytest_addopts}"}\\\
-  PYTEST_XDIST_AUTO_NUM_WORKERS=%{_smp_build_ncpus}}
+  PYTEST_XDIST_AUTO_NUM_WORKERS="${PYTEST_XDIST_AUTO_NUM_WORKERS:-%{_smp_build_ncpus}}"}
 
 %python_disable_dependency_generator() \
 %undefine __pythondist_requires \
diff --git a/macros.python3 b/macros.python3
index a813557..7197433 100644
--- a/macros.python3
+++ b/macros.python3
@@ -119,7 +119,7 @@
   PYTHONPATH="${PYTHONPATH:-%{buildroot}%{python3_sitearch}:%{buildroot}%{python3_sitelib}}"\\\
   PYTHONDONTWRITEBYTECODE=1\\\
   %{?__pytest_addopts:PYTEST_ADDOPTS="${PYTEST_ADDOPTS:-} %{__pytest_addopts}"}\\\
-  PYTEST_XDIST_AUTO_NUM_WORKERS=%{_smp_build_ncpus}}
+  PYTEST_XDIST_AUTO_NUM_WORKERS="${PYTEST_XDIST_AUTO_NUM_WORKERS:-%{_smp_build_ncpus}}"}
 
 # This is intended for Python 3 only, hence also no Python version in the name.
 %__pytest /usr/bin/pytest%(test %{python3_pkgversion} == 3 || echo -%{python3_version})
diff --git a/python-rpm-macros.spec b/python-rpm-macros.spec
index 8b5fba3..06fc622 100644
--- a/python-rpm-macros.spec
+++ b/python-rpm-macros.spec
@@ -53,7 +53,7 @@ elseif posix.stat('macros.python-srpm') then
 end
 }
 Version:        %{__default_python3_version}
-Release:        6%{?dist}
+Release:        7%{?dist}
 
 BuildArch:      noarch
 
@@ -163,6 +163,9 @@ grep -E '^#[^%%]*%%[^%%]' %{buildroot}%{rpmmacrodir}/macros.* && exit 1 || true
 
 
 %changelog
+* Thu Jan 25 2024 Miro Hrončok <mhroncok@redhat.com> - 3.12-7
+- %%py3_test_envvars: Only set $PYTEST_XDIST_AUTO_NUM_WORKERS if not already set
+
 * Mon Jan 22 2024 Fedora Release Engineering <releng@fedoraproject.org> - 3.12-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
 
diff --git a/tests/test_evals.py b/tests/test_evals.py
index 69f689e..1f953e0 100644
--- a/tests/test_evals.py
+++ b/tests/test_evals.py
@@ -324,7 +324,7 @@ def test_pytest_command_suffix_alternate_pkgversion(version):
 
 def test_pytest_sets_pytest_xdist_auto_num_workers():
     lines = rpm_eval('%pytest', _smp_build_ncpus=2)
-    assert 'PYTEST_XDIST_AUTO_NUM_WORKERS=2' in '\n'.join(lines)
+    assert 'PYTEST_XDIST_AUTO_NUM_WORKERS="${PYTEST_XDIST_AUTO_NUM_WORKERS:-2}"' in '\n'.join(lines)
 
 
 def test_pytest_undefined_addopts_are_not_set():
@@ -374,7 +374,7 @@ def test_py3_test_envvars(lib, __pytest_addopts):
     assert 'PATH="BUILDROOT/usr/bin:$PATH"' in stripped_lines
     assert 'CFLAGS="${CFLAGS:-${RPM_OPT_FLAGS}}" LDFLAGS="${LDFLAGS:-${RPM_LD_FLAGS}}"' in stripped_lines
     assert 'PYTHONDONTWRITEBYTECODE=1' in stripped_lines
-    assert 'PYTEST_XDIST_AUTO_NUM_WORKERS=3' in stripped_lines
+    assert 'PYTEST_XDIST_AUTO_NUM_WORKERS="${PYTEST_XDIST_AUTO_NUM_WORKERS:-3}"' in stripped_lines
     if __pytest_addopts:
         assert f'PYTEST_ADDOPTS="${{PYTEST_ADDOPTS:-}} {__pytest_addopts}"' in stripped_lines
     else: