diff --git a/HC.make b/HC.make
index 97c7701..6ac5301 100644
--- a/HC.make
+++ b/HC.make
@@ -4,8 +4,12 @@ HCC = hcc
 CXXFLAGS+=-O3 $(shell hcc-config --cxxflags)
 LDFLAGS+=$(shell hcc-config --ldflags)
 
+ifdef TBSIZE
+CXXFLAGS+=-DVIRTUALTILESIZE=$(TBSIZE)
+endif
+
 hc-stream: main.cpp HCStream.cpp
-	$(HCC) $(CXXFLAGS) -DHC $^  $(LDFLAGS) $(EXTRA_FLAGS) -o $@
+	$(HCC) $(CXXFLAGS) -DHC  $^  $(LDFLAGS) $(EXTRA_FLAGS) -o $@
 
 .PHONY: clean
 clean: