diff --git a/racket/src/expander/common/module-path.rkt b/racket/src/expander/common/module-path.rkt
index 5da5dd48c6..26eb0fe91c 100644
--- a/racket/src/expander/common/module-path.rkt
+++ b/racket/src/expander/common/module-path.rkt
@@ -1,5 +1,6 @@
 #lang racket/base
-(require "../compile/serialize-property.rkt"
+(require ffi/unsafe/atomic
+         "../compile/serialize-property.rkt"
          "contract.rkt"
          "parse-module-path.rkt"
          "intern.rkt")
@@ -291,11 +292,17 @@
 (define (make-generic-self-module-path-index self)
   (define r (resolved-module-path-to-generic-resolved-module-path
              (module-path-index-resolved self)))
-  (or (let ([e (hash-ref generic-self-mpis r #f)])
-        (and e (ephemeron-value e)))
-      (let ([mpi (module-path-index #f #f r #f)])
-        (hash-set! generic-self-mpis r (make-ephemeron r mpi))
-        mpi)))
+  ;; The use of `generic-self-mpis` must be atomic, so that the
+  ;; current thread cannot be killed, since that could leave
+  ;; the table locked
+  (start-atomic)
+  (begin0
+    (or (let ([e (hash-ref generic-self-mpis r #f)])
+          (and e (ephemeron-value e)))
+        (let ([mpi (module-path-index #f #f r #f)])
+          (hash-set! generic-self-mpis r (make-ephemeron r mpi))
+          mpi))
+    (end-atomic)))
 
 (define (resolved-module-path-to-generic-resolved-module-path r)
   (define name (resolved-module-path-name r))
diff --git a/racket/src/racket/src/startup.inc b/racket/src/racket/src/startup.inc
index 39a8ea0aab..364ff61414 100644
--- a/racket/src/racket/src/startup.inc
+++ b/racket/src/racket/src/startup.inc
@@ -2841,6 +2841,8 @@ static const char *startup_source =
 " for-loop_8)"
 " '#hasheq()"
 " lst_13))))))"
+"(define-values(start-atomic)(lambda()(begin(unsafe-start-atomic))))"
+"(define-values(end-atomic)(lambda()(begin(unsafe-end-atomic))))"
 "(define-values(prop:serialize serialize? serialize-ref)(make-struct-type-property 'serialize))"
 "(define-values"
 "(prop:serialize-fill! serialize-fill!? serialize-fill!-ref)"
@@ -4250,12 +4252,17 @@ static const char *startup_source =
 "(lambda(self_0)"
 "(begin"
 "(let-values(((r_15)(resolved-module-path-to-generic-resolved-module-path(module-path-index-resolved self_0))))"
+"(begin"
+"(start-atomic)"
+"(begin0"
 "(let-values(((or-part_46)"
-"(let-values(((e_9)(hash-ref generic-self-mpis r_15 #f)))(if e_9(ephemeron-value e_9) #f))))"
+"(let-values(((e_9)(hash-ref generic-self-mpis r_15 #f)))"
+"(if e_9(ephemeron-value e_9) #f))))"
 "(if or-part_46"
 " or-part_46"
 "(let-values(((mpi_6)(module-path-index2.1 #f #f r_15 #f)))"
-"(begin(hash-set! generic-self-mpis r_15(make-ephemeron r_15 mpi_6)) mpi_6))))))))"
+"(begin(hash-set! generic-self-mpis r_15(make-ephemeron r_15 mpi_6)) mpi_6))))"
+"(end-atomic)))))))"
 "(define-values"
 "(resolved-module-path-to-generic-resolved-module-path)"
 "(lambda(r_16)"