diff --git a/Makefile.in b/Makefile.in
index 62040d3..d79e2e6 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -81,7 +81,7 @@ include $(srcdir)/build/filenames.make
 #    requires you to have squirreled away a previous working version
 #    of scsh.
 
-BIG_HEAP = -h 5000000
+BIG_HEAP = -h 5500000
 # 1. is broken if you build from CVS
 # LINKER_VM = ./$(VM) $(BIG_HEAP)
 # LINKER_RUNNABLE = $(LINKER_VM) -i $(IMAGE)