diff --git a/README b/README
index 4439be11f03..baabf69c7ca 100644
--- a/README
+++ b/README
@@ -170,7 +170,7 @@ REQUIREMENTS:
         dependencies:
 
         util-linux >= v2.27.1 required
-        dbus >= 1.9.14 (strictly speaking optional, but recommended)
+        dbus >= 1.4.0 (strictly speaking optional, but recommended)
                 NOTE: If using dbus < 1.9.18, you should override the default
                 policy directory (--with-dbuspolicydir=/etc/dbus-1/system.d).
         dracut (optional)
diff --git a/src/login/pam_systemd.c b/src/login/pam_systemd.c
index c7d9dcf4e20..cdec102cea1 100644
--- a/src/login/pam_systemd.c
+++ b/src/login/pam_systemd.c
@@ -190,6 +190,40 @@ static int get_seat_from_display(const char *display, const char **seat, uint32_
         return 0;
 }
 
+static int export_legacy_dbus_address(
+                pam_handle_t *handle,
+                uid_t uid,
+                const char *runtime) {
+
+        _cleanup_free_ char *s = NULL;
+        int r = PAM_BUF_ERR;
+
+        /* FIXME: We *really* should move the access() check into the
+         * daemons that spawn dbus-daemon, instead of forcing
+         * DBUS_SESSION_BUS_ADDRESS= here. */
+
+        s = strjoin(runtime, "/bus");
+        if (!s)
+                goto error;
+
+        if (access(s, F_OK) < 0)
+                return PAM_SUCCESS;
+
+        s = mfree(s);
+        if (asprintf(&s, DEFAULT_USER_BUS_ADDRESS_FMT, runtime) < 0)
+                goto error;
+
+        r = pam_misc_setenv(handle, "DBUS_SESSION_BUS_ADDRESS", s, 0);
+        if (r != PAM_SUCCESS)
+                goto error;
+
+        return PAM_SUCCESS;
+
+error:
+        pam_syslog(handle, LOG_ERR, "Failed to set bus variable.");
+        return r;
+}
+
 static int append_session_memory_max(pam_handle_t *handle, sd_bus_message *m, const char *limit) {
         uint64_t val;
         int r;
@@ -405,6 +439,10 @@ _public_ PAM_EXTERN int pam_sm_open_session(
                         }
                 }
 
+                r = export_legacy_dbus_address(handle, pw->pw_uid, rt);
+                if (r != PAM_SUCCESS)
+                        return r;
+
                 return PAM_SUCCESS;
         }
 
@@ -613,6 +651,10 @@ _public_ PAM_EXTERN int pam_sm_open_session(
                         if (r != PAM_SUCCESS)
                                 return r;
                 }
+
+                r = export_legacy_dbus_address(handle, pw->pw_uid, runtime_path);
+                if (r != PAM_SUCCESS)
+                        return r;
         }
 
         /* Most likely we got the session/type/class from environment variables, but might have gotten the data