diff --git a/LOG b/LOG
index 79199a9c4a..6942081fb1 100644
--- a/LOG
+++ b/LOG
@@ -529,8 +529,11 @@
     bytevector.ms, root-experr*
 - fixed typo in S_abnormal_exit
     schsig.c
+- don't remove the pariah form in the cp0 pass
+    cp0.ss,
+    misc.ms
 - revert use of ephemerons in weak hashtables, add ephemeron
   hashtables
     newhash.ss, hashtable-types.ss, library.ss, primdata.ss,
     fasl.ss, fasl.c, gc.c, globals.h,
-    hash.ms, objects.stex, release_notes.stex
+    hash.ms, objects.stex, release_notes.stex
\ No newline at end of file
diff --git a/mats/misc.ms b/mats/misc.ms
index 893424dbfd..2d79db35a5 100644
--- a/mats/misc.ms
+++ b/mats/misc.ms
@@ -4865,6 +4865,17 @@
           (pariah 1)
           (* n (f (fx- n 1)))))
     3628800)
+  ; make sure that cp0 doesn't remove the pariah form
+  (not (equivalent-expansion?
+        (parameterize ([run-cp0 (lambda (cp0 x) (cp0 x))])
+          (expand/optimize
+            '(if (zero? (random 1000))
+               (pariah (display 0))
+               (display 1)))
+          (expand/optimize
+            '(if (zero? (random 1000))
+               (display 0)
+               (display 1))))))
 )
 
 (mat $read-time-stamp-counter
diff --git a/s/cp0.ss b/s/cp0.ss
index b86eec2770..a192b17442 100644
--- a/s/cp0.ss
+++ b/s/cp0.ss
@@ -1055,7 +1055,7 @@
               [(foreign ,conv ,name ,e (,arg-type* ...) ,result-type) (memoize (simple? e))]
               [(record-type ,rtd ,e) (memoize (simple? e))]
               [(record ,rtd ,rtd-expr ,e* ...) (memoize (and (simple? rtd-expr) (andmap simple? e*)))]
-              [(pariah) #t]
+              [(pariah) #f]
               [(profile ,src) #f]
               [(cte-optimization-loc ,box ,e) (memoize (simple? e))]
               [(moi) #t]