diff --git a/Makefile.config.in b/Makefile.config.in
index 96dab456119..6f91bee9300 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -133,12 +133,10 @@ AR_PATH = @AR@
 NM_PATH = @NM@
 
 # The pathnames of the programs we require to build
-BISON      := @BISON@
 CMP        := @CMP@
 CP         := @CP@
 DATE       := @DATE@
 FIND       := @FIND@
-FLEX       := @LEX@
 GREP       := @GREP@
 INSTALL    := @INSTALL@
 MKDIR      := $(LLVM_SRC_ROOT)/autoconf/mkinstalldirs
@@ -147,7 +145,6 @@ RANLIB     := @RANLIB@
 RM         := @RM@
 SED        := @SED@
 TAR        := @TAR@
-YACC       := @YACC@
 
 # Paths to miscellaneous programs we hope are present but might not be
 PERL       := @PERL@
diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 3f8d06b2d31..9b852d970ff 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -542,8 +542,6 @@ dnl Check for compilation tools
 AC_PROG_CPP
 AC_PROG_CC(gcc)
 AC_PROG_CXX(g++)
-AC_PROG_FLEX
-AC_PROG_BISON
 
 AC_PROG_NM
 AC_SUBST(NM)