diff --git a/env.ps1 b/env.ps1
index 352683c..579e208 100644
--- a/env.ps1
+++ b/env.ps1
@@ -29,7 +29,7 @@
 Function Global:dolint { flake8 src tests build.py }
 Function Global:dotest { pytest -q -n auto -x -l --sw --hypothesis-profile=dev $args }
 Function Global:dotest_ci { pytest -q -n auto --hypothesis-profile=ci }
-Function Global:dotest_long { pytest -q -n auto --hypothesis-profile=long }
+Function Global:dotest_long { pytest -q -n 4 --hypothesis-profile=long }
 Function Global:docheck { dotidy && dolint && dotest }
 Function Global:domut { mutmut run --paths-to-mutate "src/syntax.py src/tokenize.py src/parse.py" }
 Function Global:dobuild { python build.py }
diff --git a/env.sh b/env.sh
index a451fc6..d2d6f98 100644
--- a/env.sh
+++ b/env.sh
@@ -30,7 +30,7 @@
 dolint() { flake8 src tests build.py; }
 dotest() { pytest -q -n auto -x -l --sw --hypothesis-profile=dev $@; }
 dotest_ci() { pytest -q -n auto --hypothesis-profile=ci; }
-dotest_long() { pytest -q -n auto --hypothesis-profile=long; }
+dotest_long() { pytest -q -n 4 --hypothesis-profile=long; }
 docheck() { dotidy && dolint && dotest; }
 domut() { mutmut run --paths-to-mutate "src/syntax.py src/tokenize.py src/parse.py"; }
 dobuild() { python build.py; }