diff --git a/collects/mzlib/cm-accomplice.ss b/collects/mzlib/cm-accomplice.ss
index d9ceaa9..2320062 100644
--- a/collects/mzlib/cm-accomplice.ss
+++ b/collects/mzlib/cm-accomplice.ss
@@ -6,6 +6,9 @@
 		 (complete-path? f))
       (raise-type-error 'register-external-file "complete-path string" f))
     (let ([param (lambda () void)])
+      ;; Load the code in a separate thread, so that the dynamic
+      ;; extent of this one (likely a pase-sensitive macro expansion)
+      ;; doesn't pollute the load:
       (thread-wait 
        (thread (lambda ()
 		 (set! param
diff --git a/collects/mzlib/cm.ss b/collects/mzlib/cm.ss
index b5e77eb..903a64a 100644
--- a/collects/mzlib/cm.ss
+++ b/collects/mzlib/cm.ss
@@ -77,8 +77,8 @@
 	      (let ([param 
 		     ;; Avoid using cm while loading cm-ctime:
 		     (parameterize ([use-compiled-file-kinds 'none])
-		       (dynamic-require-for-syntax '(lib "cm-ctime.ss" "mzlib" "private")
-						   'current-external-file-registrar))]
+		       (dynamic-require '(lib "cm-ctime.ss" "mzlib" "private")
+					'current-external-file-registrar))]
 		    [external-deps null])
 		(let ((code (parameterize ([param (lambda (ext-file)
 						    (set! external-deps (cons ext-file external-deps)))])