diff --git a/racket/src/ChezScheme/s/arm64.def b/racket/src/ChezScheme/s/arm64.def
index de1504420d..4a48da1b23 100644
--- a/racket/src/ChezScheme/s/arm64.def
+++ b/racket/src/ChezScheme/s/arm64.def
@@ -1,11 +1,12 @@
 (define-constant architecture 'arm64)
 (define-constant ptr-bits 64)
 
-(define-constant asm-arg-reg-max 9)
+(define-constant asm-arg-reg-max 14)
 (define-constant asm-arg-reg-cnt 3)
-(define-constant asm-fpreg-max 2)
+(define-constant asm-fpreg-max 6)
 
 (define-constant native-endianness 'little)
 
 (define-constant unaligned-floats #f)
 (define-constant unaligned-integers #t)
+(define-constant integer-divide-instruction #t)
diff --git a/racket/src/ChezScheme/s/arm64.ss b/racket/src/ChezScheme/s/arm64.ss
index 000505e202..2bda5d09df 100644
--- a/racket/src/ChezScheme/s/arm64.ss
+++ b/racket/src/ChezScheme/s/arm64.ss
@@ -37,9 +37,18 @@
     [     %r5  %Carg6           #f  5 uptr]
     [     %r6  %Carg7           #f  6 uptr]
     [     %r7  %Carg8           #f  7 uptr]
+    [     %r9                   #f  9 uptr]
+    [     %r12                  #f 12 uptr]
+    [     %r13                  #f 13 uptr]
+    [     %r14                  #f 14 uptr]
+    [     %r15                  #f 15 uptr]
     [     %lr                   #f 30 uptr] ; %lr is trashed by 'c' calls including calls to hand-coded routines like get-room
-    [%fp1           %v8         #f  8 fp]
-    [%fp2           %v9         #f  9 fp]
+    [%fp1           %v16        #f 16 fp]
+    [%fp2           %v17        #f 17 fp]
+    [%fp3           %v18        #f 18 fp]
+    [%fp4           %v19        #f 19 fp]
+    [%fp5           %v20        #f 20 fp]
+    [%fp6           %v21        #f 21 fp]
   )
   (machine-dependent
     [%jmptmp %argtmp            #f 10 uptr]