diff --git a/lib/spack/spack/test/cmd/build_env.py b/lib/spack/spack/test/cmd/build_env.py
index 286fcd5e11..9a302a159c 100644
--- a/lib/spack/spack/test/cmd/build_env.py
+++ b/lib/spack/spack/test/cmd/build_env.py
@@ -25,7 +25,7 @@ def test_error_when_multiple_specs_are_given():
     assert "only takes one spec" in output
 
 
-@pytest.mark.parametrize("args", [("--", "/bin/bash", "-c", "echo test"), ("--",), ()])
+@pytest.mark.parametrize("args", [("--", "/bin/sh", "-c", "echo test"), ("--",), ()])
 @pytest.mark.usefixtures("config", "mock_packages", "working_env")
 def test_build_env_requires_a_spec(args):
     output = build_env(*args, fail_on_error=False)
@@ -35,7 +35,7 @@ def test_build_env_requires_a_spec(args):
 _out_file = "env.out"
 
 
-@pytest.mark.parametrize("shell", ["pwsh", "bat"] if sys.platform == "win32" else ["bash"])
+@pytest.mark.parametrize("shell", ["pwsh", "bat"] if sys.platform == "win32" else ["sh"])
 @pytest.mark.usefixtures("config", "mock_packages", "working_env")
 def test_dump(shell_as, shell, tmpdir):
     with tmpdir.as_cwd():
diff --git a/lib/spack/spack/test/cmd/ci.py b/lib/spack/spack/test/cmd/ci.py
index 84e9e66bf0..2695b7381f 100644
--- a/lib/spack/spack/test/cmd/ci.py
+++ b/lib/spack/spack/test/cmd/ci.py
@@ -2000,7 +2000,7 @@ def test_ci_reproduce(
 
             install_script = os.path.join(working_dir.strpath, "install.sh")
             with open(install_script, "w") as fd:
-                fd.write("#!/bin/bash\n\n#fake install\nspack install blah\n")
+                fd.write("#!/bin/sh\n\n#fake install\nspack install blah\n")
 
             spack_info_file = os.path.join(working_dir.strpath, "spack_info.txt")
             with open(spack_info_file, "w") as fd:
diff --git a/lib/spack/spack/test/compilers/basics.py b/lib/spack/spack/test/compilers/basics.py
index 512defb195..dac7622b64 100644
--- a/lib/spack/spack/test/compilers/basics.py
+++ b/lib/spack/spack/test/compilers/basics.py
@@ -253,8 +253,8 @@ def test_get_compiler_link_paths_load_env(working_env, monkeypatch, tmpdir):
     gcc = str(tmpdir.join("gcc"))
     with open(gcc, "w") as f:
         f.write(
-            """#!/bin/bash
-if [[ $ENV_SET == "1" && $MODULE_LOADED == "1" ]]; then
+            """#!/bin/sh
+if [ "$ENV_SET" = "1" ] && [ "$MODULE_LOADED" = "1" ]; then
   echo '"""
             + no_flag_output
             + """'
@@ -701,8 +701,8 @@ def test_compiler_get_real_version(working_env, monkeypatch, tmpdir):
     gcc = str(tmpdir.join("gcc"))
     with open(gcc, "w") as f:
         f.write(
-            """#!/bin/bash
-if [[ $CMP_ON == "1" ]]; then
+            """#!/bin/sh
+if [ "$CMP_ON" = "1" ]; then
     echo "$CMP_VER"
 fi
 """
@@ -747,8 +747,8 @@ def test_compiler_get_real_version_fails(working_env, monkeypatch, tmpdir):
     gcc = str(tmpdir.join("gcc"))
     with open(gcc, "w") as f:
         f.write(
-            """#!/bin/bash
-if [[ $CMP_ON == "1" ]]; then
+            """#!/bin/sh
+if [ "$CMP_ON" = "1" ]; then
     echo "$CMP_VER"
 fi
 """
@@ -801,7 +801,7 @@ def test_compiler_flags_use_real_version(working_env, monkeypatch, tmpdir):
     gcc = str(tmpdir.join("gcc"))
     with open(gcc, "w") as f:
         f.write(
-            """#!/bin/bash
+            """#!/bin/sh
 echo "4.4.4"
 """
         )  # Version for which c++11 flag is -std=c++0x