diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index b0f6d68..afe4875 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -179,26 +179,22 @@
 
 # LEX
 # ---------------------------------------------------------------------------
-LEX_PREFIX = $(if $(LEX_PREFIX_${baseprereq}),$(LEX_PREFIX_${baseprereq}),yy)
-
 quiet_cmd_flex = LEX     $@
-      cmd_flex = $(LEX) -o$@ -L -P $(LEX_PREFIX) $<
+      cmd_flex = $(LEX) -o$@ -L $<
 
 $(obj)/%.lex.c: $(src)/%.l FORCE
 	$(call if_changed,flex)
 
 # YACC
 # ---------------------------------------------------------------------------
-YACC_PREFIX = $(if $(YACC_PREFIX_${baseprereq}),$(YACC_PREFIX_${baseprereq}),yy)
-
 quiet_cmd_bison = YACC    $@
-      cmd_bison = $(YACC) -o$@ -t -l -p $(YACC_PREFIX) $<
+      cmd_bison = $(YACC) -o$@ -t -l $<
 
 $(obj)/%.tab.c: $(src)/%.y FORCE
 	$(call if_changed,bison)
 
 quiet_cmd_bison_h = YACC    $@
-      cmd_bison_h = $(YACC) -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $<
+      cmd_bison_h = $(YACC) -o/dev/null --defines=$@ -t -l $<
 
 $(obj)/%.tab.h: $(src)/%.y FORCE
 	$(call if_changed,bison_h)