diff --git a/pkgs/sagemath-environment/tox.ini b/pkgs/sagemath-environment/tox.ini
index 8af948f4676..7f08078d74e 100644
--- a/pkgs/sagemath-environment/tox.ini
+++ b/pkgs/sagemath-environment/tox.ini
@@ -1,16 +1,20 @@
 # To build and test in the tox environment:
 #
-# ./sage -sh -c '(cd pkgs/sagemath-environment && tox -v -v)'
+# ./sage -sh -c '(cd pkgs/sagemath-environment && tox -v -v -e sagepython)'
 #
 # To test interactively:
 #
-# pkgs/sagemath-environment/.tox/python/bin/python
+# pkgs/sagemath-environment/.tox/sagepython/bin/python
 #
 [tox]
+envlist =
+    sagepython-norequirements
+
 isolated_build = True
 
 [testenv]
-deps = -rrequirements.txt
+deps =
+    !norequirements: -rrequirements.txt
 
 setenv =
     # Sage scripts such as sage-runtests like to use $HOME/.sage
@@ -25,7 +29,7 @@ whitelist_externals =
 
 commands =
     # Beware of the treacherous non-src layout. "./sage/" shadows the installed sage package.
-    python -c 'import sys; "" in sys.path and sys.path.remove(""); from sage.features.all import all_features; print(sorted(all_features(), key=lambda x: x.name)); import sage.misc.package'
+    {envpython} -c 'import sys; "" in sys.path and sys.path.remove(""); from sage.features.all import all_features; print(sorted(all_features(), key=lambda x: x.name)); import sage.misc.package'
 
 [testenv:sagepython]
 passenv =
diff --git a/pkgs/sagemath-repl/tox.ini b/pkgs/sagemath-repl/tox.ini
index ff2e8e826f1..d766fa55f74 100644
--- a/pkgs/sagemath-repl/tox.ini
+++ b/pkgs/sagemath-repl/tox.ini
@@ -1,16 +1,20 @@
 # To build and test in the tox environment:
 #
-# ./sage -sh -c '(cd pkgs/sagemath-repl && tox -v -v)'
+# ./sage -sh -c '(cd pkgs/sagemath-repl && tox -v -v -e sagepython)'
 #
 # To test interactively:
 #
-# pkgs/sagemath-repl/.tox/python/bin/python
+# pkgs/sagemath-repl/.tox/sagepython/bin/python
 #
 [tox]
+envlist =
+    sagepython-norequirements
+
 isolated_build = True
 
 [testenv]
-deps = -rrequirements.txt
+deps =
+    !norequirements: -rrequirements.txt
 
 setenv =
     # Sage scripts such as sage-runtests like to use $HOME/.sage
@@ -25,9 +29,9 @@ whitelist_externals =
 
 commands =
     # Beware of the treacherous non-src layout. "./sage/" shadows the installed sage package.
-    python -c 'import sys; "" in sys.path and sys.path.remove(""); import sage.repl.all; import sage.doctest.all'
+    {envpython} -c 'import sys; "" in sys.path and sys.path.remove(""); import sage.repl.all; import sage.doctest.all'
 
-    bash -c 'cd bin && SAGE_SRC=$(python -c "from sage.env import SAGE_SRC; print(SAGE_SRC)") && sage-runtests --environment=sage.all__sagemath_repl --optional=sage $SAGE_SRC/sage/repl $SAGE_SRC/sage/doctest $SAGE_SRC/sage/misc/sage_input.py $SAGE_SRC/sage/misc/sage_eval.py || echo "(lots of doctest failures are expected)"'
+    bash -c 'cd bin && SAGE_SRC=$({envpython} -c "from sage.env import SAGE_SRC; print(SAGE_SRC)") && sage-runtests --environment=sage.all__sagemath_repl --optional=sage $SAGE_SRC/sage/repl $SAGE_SRC/sage/doctest $SAGE_SRC/sage/misc/sage_input.py $SAGE_SRC/sage/misc/sage_eval.py || echo "(lots of doctest failures are expected)"'
 
 [testenv:sagepython]
 passenv =