diff --git a/configure.ac b/configure.ac
index 4e5332750e..625bc08b08 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1305,7 +1305,6 @@ AC_SUBST(CURL)
 #
 
 LIBIDN2_CFLAGS=
-LIBIDN2_LDFLAGS=
 LIBIDN2_LIBS=
 
 # [pairwise: --with-libidn2=yes, --without-libidn2]
@@ -1318,20 +1317,18 @@ AS_CASE([$with_libidn2],
 	[no],	[],
 	[*],	[AX_SAVE_FLAGS([libidn2])
 		 LIBIDN2_CFLAGS="-I$with_libidn2/include"
-		 LIBIDN2_LDFLAGS="-L$with_libidn2/lib"
-		 CFLAGS="$LIBIDN2_CFLAGS $CFLAGS"
-		 CPPFLAGS="$LIBIDN2_CFLAGS $CPPFLAGS"
-		 LDFLAGS="$LIBIDN2_LDFLAGS $LDFLAGS"
+		 LIBIDN2_LIBS="-L$with_libidn2/lib"
+		 CFLAGS="$CFLAGS $LIBIDN2_CFLAGS"
+		 LIBS="$LIBS $LIBIDN2_LIBS"
 		 AC_CHECK_HEADERS([idn2.h],
 				  [],
 				  [AC_MSG_ERROR([idn2.h not found])])
 		 AC_SEARCH_LIBS([idn2_to_ascii_lz], [idn2],
-				[LIBIDN2_LIBS="$ac_cv_search_idn2_to_ascii_lz"
+				[LIBIDN2_LIBS="$LIBIDN2_LIBS $ac_cv_search_idn2_to_ascii_lz"
 				 AC_DEFINE([HAVE_LIBIDN2], [1], [Define if libidn2 was found])],
 				[AC_MSG_ERROR([libidn2 requested, but not found])])
 		AX_RESTORE_FLAGS([libidn2])])
 AC_SUBST([LIBIDN2_CFLAGS])
-AC_SUBST([LIBIDN2_LDFLAGS])
 AC_SUBST([LIBIDN2_LIBS])
 
 #
@@ -1456,8 +1453,6 @@ DLZ_DRIVER_LIBS=""
 DLZ_DRIVER_SRCS=""
 DLZ_DRIVER_OBJS=""
 DLZ_SYSTEM_TEST=""
-DLZ_DRIVER_MYSQL_INCLUDES=""
-DLZ_DRIVER_MYSQL_LIBS=""
 
 #
 #
@@ -1560,8 +1555,6 @@ AS_IF([test "$enable_dnsrps" != "no"],[
 # AC_SUBST(DLZ_DRIVER_SRCS)
 # AC_SUBST(DLZ_DRIVER_OBJS)
 # AC_SUBST(DLZ_SYSTEM_TEST)
-# AC_SUBST(DLZ_DRIVER_MYSQL_INCLUDES)
-# AC_SUBST(DLZ_DRIVER_MYSQL_LIBS)
 # AC_SUBST_FILE(DLZ_DRIVER_RULES)
 # this ensures the configure summary report comes out right
 test -z "$with_dlz_bdb" && with_dlz_bdb=no
diff --git a/m4/ax_lib_lmdb.m4 b/m4/ax_lib_lmdb.m4
index 2d011dc7cd..0b1c5662c5 100644
--- a/m4/ax_lib_lmdb.m4
+++ b/m4/ax_lib_lmdb.m4
@@ -12,11 +12,6 @@
 #
 #   This macro takes only one argument, a path to the lmdb headers and library.
 #
-#   This macro calls:
-#
-#     AC_SUBST(LMDB_CFLAGS)
-#     AC_SUBST(LMDB_LDFLAGS)
-#
 # LICENSE
 #
 #   Copyright (c) 2020 Internet Systems Consortium
@@ -42,8 +37,6 @@ AC_DEFUN([AX_LIB_LMDB],
 		 LIBS="$LIBS $LMDB_LIBS"
 		 AC_SEARCH_LIBS([mdb_env_create], [lmdb],
 				[LMDB_LIBS="$LMDB_LIBS $ac_cv_search_mdb_env_create"
-				 AC_SUBST([LMDB_CFLAGS])
-				 AC_SUBST([LMDB_LDFLAGS])
 				 AX_RESTORE_FLAGS([lmdb])
 				 $2
 				],