diff --git a/racket/collects/compiler/private/cm-minimal.rkt b/racket/collects/compiler/private/cm-minimal.rkt
index 9061b426f5..399784ca09 100644
--- a/racket/collects/compiler/private/cm-minimal.rkt
+++ b/racket/collects/compiler/private/cm-minimal.rkt
@@ -158,7 +158,7 @@
   (and (pair? p) (cdr p)))
 (define deps-imports cdddr)
 
-(define (get-compilation-path path->mode roots path)
+(define (get-compilation-path path->mode roots path #:for-lock? [for-lock? #f])
   (let-values ([(dir name) (get-compilation-dir+name path
                                                      #:modes (list (path->mode path))
                                                      #:roots roots
@@ -167,7 +167,8 @@
                                                      ;; may pick the first root where there's no ".dep"
                                                      ;; written yet when the second root on has a ".dep"
                                                      ;; and the ".zo" is not yet in place
-                                                     #:default-root (if (cross-multi-compile? roots)
+                                                     #:default-root (if (and (not for-lock?)
+                                                                             (cross-multi-compile? roots))
                                                                         (cadr roots)
                                                                         (car roots)))])
     (build-path dir name)))
@@ -702,6 +703,11 @@
             (touch zo-name)
             #f]
            [else
+            (define lock-zo-name (if (cross-multi-compile? roots)
+                                     ;; Make sure we use a file path for the lock that is consistent
+                                     ;; with being in a phase of compiling for the current machine:
+                                     (path-add-extension (get-compilation-path path->mode roots path) #".zo")
+                                     zo-name))
             ;; Called when `tryng-sha1?` is #f and this process (or some process)
             ;; needs to compile, recompile, or touch:
             (define (build #:just-touch? [just-touch? #f]
@@ -711,7 +717,7 @@
                            #:use-existing-deps [use-existing-deps #f])
               (define lc (parallel-lock-client))
               (when lc (log-compile-event path 'locking))
-              (define locked? (and lc (lc 'lock zo-name)))
+              (define locked? (and lc (lc 'lock lock-zo-name)))
               (define ok-to-compile? (or (not lc) locked?))
               (dynamic-wind
                (lambda () (void))
@@ -756,7 +762,7 @@
                                                [else 'finish-compile])
                                              'already-done))
                  (when locked?
-                   (lc 'unlock zo-name))))
+                   (lc 'unlock lock-zo-name))))
               #f)
             ;; Called to recompile bytecode that is currently in
             ;; machine-independent form:
@@ -776,8 +782,8 @@
             (define (build/sync)
               (define lc (parallel-lock-client))
               (when lc
-                (when (lc 'lock zo-name)
-                  (lc 'unlock zo-name)))
+                (when (lc 'lock lock-zo-name)
+                  (lc 'unlock lock-zo-name)))
               #f)
             ;; ----------------------------------------
             ;; Determine whether and how to rebuild the file: