diff --git a/Makefile b/Makefile
index 12035172..fb7efd08 100644
--- a/Makefile
+++ b/Makefile
@@ -224,6 +224,10 @@ ifndef USE_RENDERER_DLOPEN
 USE_RENDERER_DLOPEN=1
 endif
 
+ifndef USE_YACC
+USE_YACC=0
+endif
+
 ifndef DEBUG_CFLAGS
 DEBUG_CFLAGS=-ggdb -O0
 endif
@@ -1351,6 +1355,10 @@ ifndef TOOLS_CC
   TOOLS_CC = gcc
 endif
 
+ifndef YACC
+  YACC = yacc
+endif
+
 TOOLS_OPTIMIZE = -g -Wall -fno-strict-aliasing
 TOOLS_CFLAGS += $(TOOLS_OPTIMIZE) \
                 -DTEMPDIR=\"$(TEMPDIR)\" -DSYSTEM=\"\" \
@@ -1363,6 +1371,12 @@ ifeq ($(GENERATE_DEPENDENCIES),1)
   TOOLS_CFLAGS += -MMD
 endif
 
+define DO_YACC
+$(echo_cmd) "YACC $<"
+$(Q)$(YACC) $<
+$(Q)mv -f y.tab.c $@
+endef
+
 define DO_TOOLS_CC
 $(echo_cmd) "TOOLS_CC $<"
 $(Q)$(TOOLS_CC) $(TOOLS_CFLAGS) -o $@ -c $<
@@ -1384,6 +1398,12 @@ LBURGOBJ= \
   $(B)/tools/lburg/lburg.o \
   $(B)/tools/lburg/gram.o
 
+# override GNU Make built-in rule for converting gram.y to gram.c
+%.c: %.y
+ifeq ($(USE_YACC),1)
+	$(DO_YACC)
+endif
+
 $(B)/tools/lburg/%.o: $(LBURGDIR)/%.c
 	$(DO_TOOLS_CC)
 
diff --git a/README.md b/README.md
index a5dacc9c..3e004ad8 100644
--- a/README.md
+++ b/README.md
@@ -89,6 +89,7 @@ Makefile.local:
   SERVERBIN            - rename 'ioq3ded' server binary
   CLIENTBIN            - rename 'ioquake3' client binary
   USE_RENDERER_DLOPEN  - build and use the renderer in a library
+  USE_YACC             - use yacc to update code/tools/lcc/lburg/gram.c
   BASEGAME             - rename 'baseq3'
   BASEGAME_CFLAGS      - custom CFLAGS for basegame
   MISSIONPACK          - rename 'missionpack'