--- invoke/config.py.orig	2025-10-13 23:49:45 UTC
+++ invoke/config.py
@@ -440,16 +440,16 @@ class Config(DataProxy):
 
         .. versionadded:: 1.0
         """
-        # On Windows, which won't have /bin/bash, check for a set COMSPEC env
+        # On Windows, which won't have /bin/sh, check for a set COMSPEC env
         # var (https://en.wikipedia.org/wiki/COMSPEC) or fallback to an
         # unqualified cmd.exe otherwise.
         if WINDOWS:
             shell = os.environ.get("COMSPEC", "cmd.exe")
-        # Else, assume Unix, most distros of which have /bin/bash available.
+        # Else, assume Unix, most distros of which have /bin/sh available.
         # TODO: consider an automatic fallback to /bin/sh for systems lacking
-        # /bin/bash; however users may configure run.shell quite easily, so...
+        # /bin/sh; however users may configure run.shell quite easily, so...
         else:
-            shell = "bash"
+            shell = "sh"
 
         return {
             # TODO: we document 'debug' but it's not truly implemented outside
--- invoke/runners.py.orig	2026-04-05 23:27:54 UTC
+++ invoke/runners.py
@@ -342,7 +342,7 @@ class Runner:
             Default: ``False``.
 
         :param str shell:
-            Which shell binary to use. Default: ``/bin/bash`` (on Unix;
+            Which shell binary to use. Default: ``/bin/sh`` (on Unix;
             ``COMSPEC`` or ``cmd.exe`` on Windows.)
 
         :param timeout:
--- tests/config.py.orig	2025-10-14 01:23:47 UTC
+++ tests/config.py
@@ -107,7 +107,7 @@ class Config_:
                     "out_stream": None,
                     "pty": False,
                     "replace_env": False,
-                    "shell": "bash",
+                    "shell": "sh",
                     "warn": False,
                     "watchers": [],
                 },
--- tests/runners.py.orig	2026-04-05 23:27:54 UTC
+++ tests/runners.py
@@ -81,7 +81,7 @@ def _expect_platform_shell(shell):
     if WINDOWS:
         assert shell.endswith("cmd.exe")
     else:
-        assert shell == "bash"
+        assert shell == "sh"
 
 
 def _make_tcattrs(cc_is_ints=True, echo=False):