diff --git a/tox.ini b/tox.ini
index a7bdab16e..8bae5ce5f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -322,7 +322,9 @@ deps =
     {[testenv]deps}
     botocore>=1.13.45
 commands =
-    delta run -- {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=botocore.junit.xml -o junit_family=legacy} -m requires_botocore
+    # Not using delta run here: tests are already marker-filtered to -m requires_botocore.
+    # Delta selecting non-botocore tests then filtering by marker yields exit code 5 (no tests collected).
+    pytest {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=botocore.junit.xml -o junit_family=legacy} -m requires_botocore
 
 [testenv:min-botocore]
 basepython = {[min]basepython}
@@ -334,7 +336,8 @@ deps =
 setenv =
     {[min]setenv}
 commands =
-    delta run -- {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=min-botocore.junit.xml -o junit_family=legacy} -m requires_botocore
+    # Not using delta run here: tests are already marker-filtered to -m requires_botocore.
+    pytest {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=min-botocore.junit.xml -o junit_family=legacy} -m requires_botocore
 
 
 # Run proxy tests that use mitmproxy in a separate env to avoid installing
@@ -348,4 +351,6 @@ deps =
     mitmproxy; implementation_name != "pypy"
     httpx[http2,socks]
 commands =
-    delta run -- {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=mitmproxy.junit.xml -o junit_family=legacy} -m requires_mitmproxy
+    # Not using delta run here: tests are already marker-filtered to -m requires_mitmproxy.
+    # Delta selecting non-mitmproxy tests then filtering by marker yields exit code 5 (no tests collected).
+    pytest {posargs:--cov-config=pyproject.toml --cov=scrapy --cov-report=xml --cov-report= tests --junitxml=mitmproxy.junit.xml -o junit_family=legacy} -m requires_mitmproxy