diff --git a/aider/utils.py b/aider/utils.py
index 48849f567..858c57649 100644
--- a/aider/utils.py
+++ b/aider/utils.py
@@ -1,5 +1,6 @@
 import itertools
 import os
+import shlex
 import subprocess
 import sys
 import tempfile
@@ -314,7 +315,7 @@ def check_pip_install_extra(io, module, prompt, pip_install_cmd):
     if prompt:
         io.tool_error(prompt)
 
-    if not io.confirm_ask("Run pip install?", default="y", subject=" ".join(cmd)):
+    if not io.confirm_ask("Run pip install?", default="y", subject=shlex.join(cmd)):
         return
 
     success, output = run_install(cmd)
diff --git a/aider/versioncheck.py b/aider/versioncheck.py
index 883fd82f1..83221139a 100644
--- a/aider/versioncheck.py
+++ b/aider/versioncheck.py
@@ -1,4 +1,5 @@
 import os
+import shlex
 import sys
 import time
 from pathlib import Path
@@ -96,7 +97,7 @@ Newer aider version v{latest_version} is available. To upgrade, run:
     text = f"Newer aider version v{latest_version} is available. To upgrade, run:"
 
     io.tool_error(text)
-    if io.confirm_ask("Run pip install?", subject=" ".join(cmd)):
+    if io.confirm_ask("Run pip install?", subject=shlex.join(cmd)):
         success, output = utils.run_install(cmd)
         if success:
             io.tool_output("Re-run aider to use new version.")