diff --git a/configure.in b/configure.in
index 30f8c1550..c05de97ef 100644
--- a/configure.in
+++ b/configure.in
@@ -25,7 +25,7 @@ AC_PROG_CC
 
 dnl AC_KRB_PROG_YACC
 AC_PROG_YACC
-AC_PROG_LEX
+AM_PROG_LEX
 AC_PROG_RANLIB
 AC_PROG_AWK
 AC_KRB_PROG_LN_S
@@ -199,7 +199,6 @@ AC_TYPE_MODE_T
 AC_TYPE_SIG_ATOMIC_T
 AC_HEADER_TIME
 AC_STRUCT_TM
-AC_DECL_YYTEXT
 
 dnl Checks for header files.
 AC_HEADER_STDC