diff --git a/lib/pip.js b/lib/pip.js
index 7a0a0ceb..2cb9ac43 100644
--- a/lib/pip.js
+++ b/lib/pip.js
@@ -41,7 +41,7 @@ function mergeCommands(commands) {
   } else {
     // Quote the arguments in each command and join them all using &&.
     const script = cmds.map(quote).join(' && ');
-    return ['/bin/sh', '-c', script];
+    return ['/bin/sh', '-c', '"' + script + '"'];
   }
 }