diff --git a/regex.tal b/regex.tal
index 556c70b..ff477ad 100644
--- a/regex.tal
+++ b/regex.tal
@@ -698,7 +698,7 @@
 
 ( stack-bot is the address of the first stack position. )
 ( stack-top is the address of the first byte beyond the stack. )
-@stack-bot $1000 @stack-top ( holds 1024 steps (4096 bytes) )
+@stack-bot $0800 @stack-top ( holds 512 steps (2048 bytes) )
 
 ( ARENA OPERATIONS )
 ( )
@@ -785,7 +785,7 @@
               INC2 INC2 ,&loop JMP
 
 @subgroup-pos :subgroup-bot ( the position of the first unallocated subgroup )
-@subgroup-bot $800 @subgroup-top ( holds up to 512 subgroups (2048 bytes) )
+@subgroup-bot $400 @subgroup-top ( holds up to 256 subgroups (1024 bytes) )
 
 ( INTERVAL OPERATIONS )
 ( )