diff --git a/src/env.cpp b/src/env.cpp
index d5798f4b9..2819d78ed 100644
--- a/src/env.cpp
+++ b/src/env.cpp
@@ -1306,6 +1306,14 @@ std::shared_ptr<environment_t> env_stack_t::snapshot() const { return acquire_im
 
 void env_stack_t::set_argv(wcstring_list_t argv) { set(L"argv", ENV_LOCAL, std::move(argv)); }
 
+wcstring env_stack_t::get_pwd_slash() const {
+    wcstring pwd = acquire_impl()->perproc_data().pwd;
+    if (!string_suffixes_string(L"/", pwd)) {
+        pwd.push_back(L'/');
+    }
+    return pwd;
+}
+
 void env_stack_t::push(bool new_scope) {
     auto impl = acquire_impl();
     if (new_scope) {
diff --git a/src/env.h b/src/env.h
index d65f66c98..873bfeaa6 100644
--- a/src/env.h
+++ b/src/env.h
@@ -199,7 +199,7 @@ class environment_t {
     virtual ~environment_t();
 
     /// Returns the PWD with a terminating slash.
-    wcstring get_pwd_slash() const;
+    virtual wcstring get_pwd_slash() const;
 };
 
 /// The null environment contains nothing.
@@ -296,6 +296,9 @@ class env_stack_t final : public environment_t {
     /// Sets up argv as the given list of strings.
     void set_argv(wcstring_list_t argv);
 
+    /// Slightly optimized implementation.
+    wcstring get_pwd_slash() const override;
+
     // Compatibility hack; access the "environment stack" from back when there was just one.
     static const std::shared_ptr<env_stack_t> &principal_ref();
     static env_stack_t &principal() { return *principal_ref(); }