diff --git a/b2/_internal/_cli/autocomplete_install.py b/b2/_internal/_cli/autocomplete_install.py
index f0e6bb1f..ade16130 100644
--- a/b2/_internal/_cli/autocomplete_install.py
+++ b/b2/_internal/_cli/autocomplete_install.py
@@ -193,22 +193,25 @@ def is_enabled(self) -> bool:
         That alone cannot be used, since fish tends to always propose completions (e.g. suggesting similarly
         named filenames).
         """
+        environ = os.environ.copy()
+        environ.setdefault("TERM", "xterm")  # TERM has to be set for fish to load completions
         return _silent_success_run(
             [
                 self.shell_exec, '-i', '-c',
                 f'string length -q -- (complete -C{quote(f"{self.prog} ")} >/dev/null && complete -c {quote(self.prog)})'
-            ]
+            ],
+            env=environ,
         )
 
 
-def _silent_success_run(cmd: list[str], timeout: int | None = 60) -> bool:
-    # start_new_session prevents `zsh -i` interaction with parent terminal under pytest-xdist
+def _silent_success_run(cmd: list[str], timeout: int | None = 60, env: dict | None = None) -> bool:
     p = subprocess.Popen(
         cmd,
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
         stdin=subprocess.DEVNULL,
-        start_new_session=True,
+        start_new_session=True,  # prevents `zsh -i` messing with parent tty under pytest-xdist
+        env=env,
     )
 
     try:
diff --git a/test/unit/conftest.py b/test/unit/conftest.py
index 2aebc15c..9e40d938 100644
--- a/test/unit/conftest.py
+++ b/test/unit/conftest.py
@@ -53,6 +53,8 @@ def env(homedir, monkeypatch):
     """Get ENV for running b2 command from shell level."""
     monkeypatch.setenv("HOME", str(homedir))
     monkeypatch.setenv("SHELL", "/bin/bash")  # fix for running under github actions
+    if "TERM" not in os.environ:
+        monkeypatch.setenv("TERM", "xterm")
     yield os.environ
 
 
diff --git a/test/unit/console_tool/test_install_autocomplete.py b/test/unit/console_tool/test_install_autocomplete.py
index 3f3caa3d..bbf3fd6c 100644
--- a/test/unit/console_tool/test_install_autocomplete.py
+++ b/test/unit/console_tool/test_install_autocomplete.py
@@ -37,9 +37,6 @@ def test_install_autocomplete(b2_cli, env, shell, monkeypatch):
         expected_part_of_stdout=f"Autocomplete successfully installed for {shell}",
     )
 
-    if shell == "fish":  # no idea how to test fish autocompletion (does not seem to work with dummy terminal)
-        return
-
     with pexpect_shell(shell_bin, env=env) as pshell:
         pshell.send("b2 \t\t")
         pshell.expect_exact(["authorize-account", "download-file", "get-bucket"], timeout=30)