diff --git a/ext/bz2/config.m4 b/ext/bz2/config.m4
index 56d81a60d7951..db812266dd67f 100644
--- a/ext/bz2/config.m4
+++ b/ext/bz2/config.m4
@@ -34,5 +34,5 @@ if test "$PHP_BZ2" != "no"; then
   ])
 
   PHP_NEW_EXTENSION(bz2, bz2.c bz2_filter.c, $ext_shared)
-  PHP_SUBST(BZ2_SHARED_LIBADD)
+  PHP_SUBST([BZ2_SHARED_LIBADD])
 fi
diff --git a/ext/curl/config.m4 b/ext/curl/config.m4
index 786113e58a4c1..ad8f01e6cf6d3 100644
--- a/ext/curl/config.m4
+++ b/ext/curl/config.m4
@@ -84,5 +84,5 @@ if test "$PHP_CURL" != "no"; then
 
   PHP_NEW_EXTENSION(curl, interface.c multi.c share.c curl_file.c, $ext_shared)
   PHP_INSTALL_HEADERS([ext/curl], [php_curl.h])
-  PHP_SUBST(CURL_SHARED_LIBADD)
+  PHP_SUBST([CURL_SHARED_LIBADD])
 fi
diff --git a/ext/dba/config.m4 b/ext/dba/config.m4
index 920b891405243..267ee1aa7a646 100644
--- a/ext/dba/config.m4
+++ b/ext/dba/config.m4
@@ -705,7 +705,7 @@ if test "$HAVE_DBA" = "1"; then
   PHP_ADD_BUILD_DIR($ext_builddir/libinifile)
   PHP_ADD_BUILD_DIR($ext_builddir/libcdb)
   PHP_ADD_BUILD_DIR($ext_builddir/libflatfile)
-  PHP_SUBST(DBA_SHARED_LIBADD)
+  PHP_SUBST([DBA_SHARED_LIBADD])
 else
   AC_MSG_RESULT(no)
 fi
diff --git a/ext/dom/config.m4 b/ext/dom/config.m4
index 12b6bdba745f5..4c5a5eb121d53 100644
--- a/ext/dom/config.m4
+++ b/ext/dom/config.m4
@@ -54,7 +54,7 @@ if test "$PHP_DOM" != "no"; then
     PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/selectors-adapted)
     PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/ns)
     PHP_ADD_BUILD_DIR($ext_builddir/$LEXBOR_DIR/tag)
-    PHP_SUBST(DOM_SHARED_LIBADD)
+    PHP_SUBST([DOM_SHARED_LIBADD])
     PHP_INSTALL_HEADERS([ext/dom], [xml_common.h xpath_callbacks.h namespace_compat.h])
     PHP_ADD_EXTENSION_DEP(dom, libxml)
   ])
diff --git a/ext/enchant/config.m4 b/ext/enchant/config.m4
index 949db83247d30..5c21fe242ec59 100644
--- a/ext/enchant/config.m4
+++ b/ext/enchant/config.m4
@@ -38,5 +38,5 @@ if test "$PHP_ENCHANT" != "no"; then
   AC_DEFINE(HAVE_ENCHANT, 1, [ ])
 
   PHP_NEW_EXTENSION(enchant, enchant.c, $ext_shared)
-  PHP_SUBST(ENCHANT_SHARED_LIBADD)
+  PHP_SUBST([ENCHANT_SHARED_LIBADD])
 fi
diff --git a/ext/ffi/config.m4 b/ext/ffi/config.m4
index 76b8dc5bb766a..81f7e500b8471 100644
--- a/ext/ffi/config.m4
+++ b/ext/ffi/config.m4
@@ -28,5 +28,5 @@ if test "$PHP_FFI" != "no"; then
   PHP_FFI_CHECK_DECL([FFI_SYSV])
 
   PHP_NEW_EXTENSION(ffi, ffi.c ffi_parser.c, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(FFI_SHARED_LIBADD)
+  PHP_SUBST([FFI_SHARED_LIBADD])
 fi
diff --git a/ext/ftp/config.m4 b/ext/ftp/config.m4
index 150ed651bb899..1ad42a0510ba3 100644
--- a/ext/ftp/config.m4
+++ b/ext/ftp/config.m4
@@ -21,7 +21,7 @@ if test "$PHP_FTP" = "yes"; then
 
   if test "$PHP_OPENSSL" != "no" || test "$PHP_FTP_SSL" != "no"; then
     PHP_SETUP_OPENSSL(FTP_SHARED_LIBADD)
-    PHP_SUBST(FTP_SHARED_LIBADD)
+    PHP_SUBST([FTP_SHARED_LIBADD])
     AC_DEFINE(HAVE_FTP_SSL,1,[Whether FTP over SSL is supported])
   fi
 fi
diff --git a/ext/gettext/config.m4 b/ext/gettext/config.m4
index 9e304d82b8d29..c2292d9351b83 100644
--- a/ext/gettext/config.m4
+++ b/ext/gettext/config.m4
@@ -33,7 +33,7 @@ if test "$PHP_GETTEXT" != "no"; then
 
   AC_DEFINE(HAVE_LIBINTL,1,[ ])
   PHP_NEW_EXTENSION(gettext, gettext.c, $ext_shared)
-  PHP_SUBST(GETTEXT_SHARED_LIBADD)
+  PHP_SUBST([GETTEXT_SHARED_LIBADD])
 
   PHP_ADD_INCLUDE($GETTEXT_INCDIR)
 
diff --git a/ext/gmp/config.m4 b/ext/gmp/config.m4
index 657e43b407fa7..66faf2c43dca5 100644
--- a/ext/gmp/config.m4
+++ b/ext/gmp/config.m4
@@ -30,6 +30,6 @@ if test "$PHP_GMP" != "no"; then
   PHP_INSTALL_HEADERS([ext/gmp], [php_gmp_int.h])
 
   PHP_NEW_EXTENSION(gmp, gmp.c, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(GMP_SHARED_LIBADD)
+  PHP_SUBST([GMP_SHARED_LIBADD])
   AC_DEFINE(HAVE_GMP, 1, [ ])
 fi
diff --git a/ext/iconv/config.m4 b/ext/iconv/config.m4
index 6fd60b90838a4..72591f752d0bf 100644
--- a/ext/iconv/config.m4
+++ b/ext/iconv/config.m4
@@ -133,7 +133,7 @@ int main(void) {
     CFLAGS="$save_CFLAGS"
 
     PHP_NEW_EXTENSION(iconv, iconv.c, $ext_shared,, [-DZEND_ENABLE_STATIC_TSRMLS_CACHE=1])
-    PHP_SUBST(ICONV_SHARED_LIBADD)
+    PHP_SUBST([ICONV_SHARED_LIBADD])
     PHP_INSTALL_HEADERS([ext/iconv], [php_iconv.h])
   else
     AC_MSG_ERROR(Please reinstall the iconv library.)
diff --git a/ext/intl/config.m4 b/ext/intl/config.m4
index 78396dc416926..98ac6f40dc489 100644
--- a/ext/intl/config.m4
+++ b/ext/intl/config.m4
@@ -5,7 +5,7 @@ PHP_ARG_ENABLE([intl],
 
 if test "$PHP_INTL" != "no"; then
   PHP_SETUP_ICU(INTL_SHARED_LIBADD)
-  PHP_SUBST(INTL_SHARED_LIBADD)
+  PHP_SUBST([INTL_SHARED_LIBADD])
   INTL_COMMON_FLAGS="$ICU_CFLAGS -Wno-write-strings -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1"
   PHP_NEW_EXTENSION(intl, php_intl.c \
     intl_error.c \
diff --git a/ext/ldap/config.m4 b/ext/ldap/config.m4
index 18178c8cf77d4..a29c07d07e1ea 100644
--- a/ext/ldap/config.m4
+++ b/ext/ldap/config.m4
@@ -92,7 +92,7 @@ if test "$PHP_LDAP" != "no"; then
   fi
 
   PHP_ADD_INCLUDE($LDAP_INCDIR)
-  PHP_SUBST(LDAP_SHARED_LIBADD)
+  PHP_SUBST([LDAP_SHARED_LIBADD])
   AC_DEFINE(HAVE_LDAP,1,[ ])
 
   dnl Save original values
diff --git a/ext/mbstring/config.m4 b/ext/mbstring/config.m4
index 2a43e6ad2f816..4dd6948d21083 100644
--- a/ext/mbstring/config.m4
+++ b/ext/mbstring/config.m4
@@ -24,7 +24,7 @@ AC_DEFUN([PHP_MBSTRING_ADD_INSTALL_HEADERS], [
 
 AC_DEFUN([PHP_MBSTRING_EXTENSION], [
   PHP_NEW_EXTENSION(mbstring, $PHP_MBSTRING_BASE_SOURCES $PHP_MBSTRING_SOURCES, $ext_shared,, $PHP_MBSTRING_CFLAGS -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(MBSTRING_SHARED_LIBADD)
+  PHP_SUBST([MBSTRING_SHARED_LIBADD])
 
   for dir in $PHP_MBSTRING_EXTRA_BUILD_DIRS; do
     PHP_ADD_BUILD_DIR([$ext_builddir/$dir], 1)
diff --git a/ext/opcache/config.m4 b/ext/opcache/config.m4
index abccea936edce..1db5e66016606 100644
--- a/ext/opcache/config.m4
+++ b/ext/opcache/config.m4
@@ -93,9 +93,9 @@ if test "$PHP_OPCACHE" != "no"; then
       ])
     ])
 
-    PHP_SUBST(IR_TARGET)
-    PHP_SUBST(DASM_FLAGS)
-    PHP_SUBST(DASM_ARCH)
+    PHP_SUBST([IR_TARGET])
+    PHP_SUBST([DASM_FLAGS])
+    PHP_SUBST([DASM_ARCH])
 
     JIT_CFLAGS="-I@ext_builddir@/jit/ir -D${IR_TARGET} -DIR_PHP"
     if test "$ZEND_DEBUG" = "yes"; then
@@ -350,5 +350,5 @@ int main(void) {
     PHP_ADD_BUILD_DIR([$ext_builddir/jit/ir], 1)
     PHP_ADD_MAKEFILE_FRAGMENT($ext_srcdir/jit/Makefile.frag)
   fi
-  PHP_SUBST(OPCACHE_SHARED_LIBADD)
+  PHP_SUBST([OPCACHE_SHARED_LIBADD])
 fi
diff --git a/ext/openssl/config0.m4 b/ext/openssl/config0.m4
index 9e0e4f7593496..0b2fe13b068d3 100644
--- a/ext/openssl/config0.m4
+++ b/ext/openssl/config0.m4
@@ -19,7 +19,7 @@ PHP_ARG_WITH([openssl-legacy-provider],
 
 if test "$PHP_OPENSSL" != "no"; then
   PHP_NEW_EXTENSION(openssl, openssl.c xp_ssl.c, $ext_shared)
-  PHP_SUBST(OPENSSL_SHARED_LIBADD)
+  PHP_SUBST([OPENSSL_SHARED_LIBADD])
   PHP_SETUP_OPENSSL([OPENSSL_SHARED_LIBADD],
     [AC_DEFINE([HAVE_OPENSSL_EXT], [1],
       [Define to 1 if the openssl extension is available.])])
diff --git a/ext/pdo_dblib/config.m4 b/ext/pdo_dblib/config.m4
index 3cbadfee05c8b..3bf1a6cd4223b 100644
--- a/ext/pdo_dblib/config.m4
+++ b/ext/pdo_dblib/config.m4
@@ -45,7 +45,7 @@ if test "$PHP_PDO_DBLIB" != "no"; then
 
   PDO_DBLIB_DEFS="-DPDO_DBLIB_FLAVOUR=\\\"freetds\\\""
   PHP_NEW_EXTENSION(pdo_dblib, pdo_dblib.c dblib_driver.c dblib_stmt.c, $ext_shared,, $PDO_DBLIB_DEFS -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(PDO_DBLIB_SHARED_LIBADD)
+  PHP_SUBST([PDO_DBLIB_SHARED_LIBADD])
 
   PHP_ADD_EXTENSION_DEP(pdo_dblib, pdo)
 fi
diff --git a/ext/pdo_firebird/config.m4 b/ext/pdo_firebird/config.m4
index b8352ec997a01..db1fd23c05b16 100644
--- a/ext/pdo_firebird/config.m4
+++ b/ext/pdo_firebird/config.m4
@@ -61,6 +61,6 @@ if test "$PHP_PDO_FIREBIRD" != "no"; then
   PHP_CHECK_PDO_INCLUDES
 
   PHP_NEW_EXTENSION(pdo_firebird, pdo_firebird.c firebird_driver.c firebird_statement.c, $ext_shared)
-  PHP_SUBST(PDO_FIREBIRD_SHARED_LIBADD)
+  PHP_SUBST([PDO_FIREBIRD_SHARED_LIBADD])
   PHP_ADD_EXTENSION_DEP(pdo_firebird, pdo)
 fi
diff --git a/ext/pdo_mysql/config.m4 b/ext/pdo_mysql/config.m4
index 9465d61496b17..6d69362ba6f2b 100644
--- a/ext/pdo_mysql/config.m4
+++ b/ext/pdo_mysql/config.m4
@@ -94,5 +94,5 @@ if test "$PHP_PDO_MYSQL" != "no"; then
     PHP_ADD_EXTENSION_DEP(pdo_mysql, mysqlnd)
   fi
 
-  PHP_SUBST(PDO_MYSQL_SHARED_LIBADD)
+  PHP_SUBST([PDO_MYSQL_SHARED_LIBADD])
 fi
diff --git a/ext/pdo_odbc/config.m4 b/ext/pdo_odbc/config.m4
index 0feb0bb230cf0..4377ab4a3bb95 100644
--- a/ext/pdo_odbc/config.m4
+++ b/ext/pdo_odbc/config.m4
@@ -132,6 +132,6 @@ functions required for PDO support.
   ], $PDO_ODBC_LDFLAGS)
 
   PHP_NEW_EXTENSION(pdo_odbc, pdo_odbc.c odbc_driver.c odbc_stmt.c, $ext_shared,, $PDO_ODBC_INCLUDE)
-  PHP_SUBST(PDO_ODBC_SHARED_LIBADD)
+  PHP_SUBST([PDO_ODBC_SHARED_LIBADD])
   PHP_ADD_EXTENSION_DEP(pdo_odbc, pdo)
 fi
diff --git a/ext/pdo_sqlite/config.m4 b/ext/pdo_sqlite/config.m4
index 17b2fca8a1e42..ae65c4a4f909f 100644
--- a/ext/pdo_sqlite/config.m4
+++ b/ext/pdo_sqlite/config.m4
@@ -28,7 +28,7 @@ if test "$PHP_PDO_SQLITE" != "no"; then
     [$PDO_SQLITE_SHARED_LIBADD]
   )
 
-  PHP_SUBST(PDO_SQLITE_SHARED_LIBADD)
+  PHP_SUBST([PDO_SQLITE_SHARED_LIBADD])
   PHP_NEW_EXTENSION(pdo_sqlite, pdo_sqlite.c sqlite_driver.c sqlite_statement.c sqlite_sql_parser.c,
     $ext_shared)
 
diff --git a/ext/readline/config.m4 b/ext/readline/config.m4
index 209f92b6e0a76..90388fe42cd94 100644
--- a/ext/readline/config.m4
+++ b/ext/readline/config.m4
@@ -139,5 +139,5 @@ fi
 if test "$PHP_READLINE" != "no" || test "$PHP_LIBEDIT" != "no"; then
   dnl Add -Wno-strict-prototypes as depends on user libs
   PHP_NEW_EXTENSION(readline, readline.c readline_cli.c, $ext_shared, cli, "-Wno-strict-prototypes")
-  PHP_SUBST(READLINE_SHARED_LIBADD)
+  PHP_SUBST([READLINE_SHARED_LIBADD])
 fi
diff --git a/ext/session/config.m4 b/ext/session/config.m4
index 2ba655bfe85ff..36314f6db6b5a 100644
--- a/ext/session/config.m4
+++ b/ext/session/config.m4
@@ -17,7 +17,7 @@ if test "$PHP_SESSION" != "no"; then
   PHP_NEW_EXTENSION(session, mod_user_class.c session.c mod_files.c mod_mm.c mod_user.c, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
   dnl https://bugs.php.net/53141
   PHP_ADD_EXTENSION_DEP(session, spl, true)
-  PHP_SUBST(SESSION_SHARED_LIBADD)
+  PHP_SUBST([SESSION_SHARED_LIBADD])
   PHP_INSTALL_HEADERS([ext/session], [php_session.h mod_files.h mod_user.h])
   AC_DEFINE(HAVE_PHP_SESSION,1,[ ])
 fi
diff --git a/ext/simplexml/config.m4 b/ext/simplexml/config.m4
index 72c64aa49d1d8..8dd7d8a837b26 100644
--- a/ext/simplexml/config.m4
+++ b/ext/simplexml/config.m4
@@ -11,6 +11,6 @@ if test "$PHP_SIMPLEXML" != "no"; then
     PHP_ADD_EXTENSION_DEP(simplexml, libxml)
     PHP_ADD_EXTENSION_DEP(simplexml, spl)
     PHP_INSTALL_HEADERS([ext/simplexml], [php_simplexml.h php_simplexml_exports.h])
-    PHP_SUBST(SIMPLEXML_SHARED_LIBADD)
+    PHP_SUBST([SIMPLEXML_SHARED_LIBADD])
   ])
 fi
diff --git a/ext/skeleton/config.m4.in b/ext/skeleton/config.m4.in
index cc7c6354bb61e..80e0a84ec7e90 100644
--- a/ext/skeleton/config.m4.in
+++ b/ext/skeleton/config.m4.in
@@ -85,7 +85,7 @@ if test "$PHP_%EXTNAMECAPS%" != "no"; then
   dnl   -L$%EXTNAMECAPS%_DIR/$PHP_LIBDIR -lm
   dnl ])
   dnl
-  dnl PHP_SUBST(%EXTNAMECAPS%_SHARED_LIBADD)
+  dnl PHP_SUBST([%EXTNAMECAPS%_SHARED_LIBADD])
 
   dnl In case of no dependencies
   AC_DEFINE(HAVE_%EXTNAMECAPS%, 1, [ Have %EXTNAME% support ])
diff --git a/ext/snmp/config.m4 b/ext/snmp/config.m4
index f285a572de9cb..5ad3766f862a1 100644
--- a/ext/snmp/config.m4
+++ b/ext/snmp/config.m4
@@ -71,5 +71,5 @@ if test "$PHP_SNMP" != "no"; then
   ])
 
   PHP_NEW_EXTENSION(snmp, snmp.c, $ext_shared)
-  PHP_SUBST(SNMP_SHARED_LIBADD)
+  PHP_SUBST([SNMP_SHARED_LIBADD])
 fi
diff --git a/ext/soap/config.m4 b/ext/soap/config.m4
index a83424ef39702..b211cdab9f418 100644
--- a/ext/soap/config.m4
+++ b/ext/soap/config.m4
@@ -7,7 +7,7 @@ if test "$PHP_SOAP" != "no"; then
   PHP_SETUP_LIBXML(SOAP_SHARED_LIBADD, [
     AC_DEFINE(HAVE_SOAP,1,[ ])
     PHP_NEW_EXTENSION(soap, soap.c php_encoding.c php_http.c php_packet_soap.c php_schema.c php_sdl.c php_xml.c, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-    PHP_SUBST(SOAP_SHARED_LIBADD)
+    PHP_SUBST([SOAP_SHARED_LIBADD])
   ])
   PHP_ADD_EXTENSION_DEP(soap, libxml)
   PHP_ADD_EXTENSION_DEP(soap, session, true)
diff --git a/ext/sodium/config.m4 b/ext/sodium/config.m4
index 4adb695b457e5..50ccf23573d03 100644
--- a/ext/sodium/config.m4
+++ b/ext/sodium/config.m4
@@ -23,5 +23,5 @@ if test "$PHP_SODIUM" != "no"; then
 
   PHP_NEW_EXTENSION(sodium, libsodium.c sodium_pwhash.c, $ext_shared, , $SODIUM_COMPILER_FLAGS)
   PHP_INSTALL_HEADERS([ext/sodium], [php_libsodium.h])
-  PHP_SUBST(SODIUM_SHARED_LIBADD)
+  PHP_SUBST([SODIUM_SHARED_LIBADD])
 fi
diff --git a/ext/sqlite3/config0.m4 b/ext/sqlite3/config0.m4
index 72d72d4ffe4e4..92ed6bb56e811 100644
--- a/ext/sqlite3/config0.m4
+++ b/ext/sqlite3/config0.m4
@@ -23,5 +23,5 @@ if test $PHP_SQLITE3 != "no"; then
   )
 
   PHP_NEW_EXTENSION(sqlite3, sqlite3.c, $ext_shared,,-DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(SQLITE3_SHARED_LIBADD)
+  PHP_SUBST([SQLITE3_SHARED_LIBADD])
 fi
diff --git a/ext/tidy/config.m4 b/ext/tidy/config.m4
index bc0976a1dd9b3..f48d25141e2b4 100644
--- a/ext/tidy/config.m4
+++ b/ext/tidy/config.m4
@@ -68,6 +68,6 @@ if test "$PHP_TIDY" != "no"; then
   dnl Add -Wno-ignored-qualifiers as this is an issue upstream
   TIDY_COMPILER_FLAGS="$TIDY_CFLAGS -Wno-ignored-qualifiers -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1"
   PHP_NEW_EXTENSION(tidy, tidy.c, $ext_shared,, $TIDY_COMPILER_FLAGS)
-  PHP_SUBST(TIDY_SHARED_LIBADD)
+  PHP_SUBST([TIDY_SHARED_LIBADD])
   AC_DEFINE(HAVE_TIDY,1,[ ])
 fi
diff --git a/ext/xml/config.m4 b/ext/xml/config.m4
index 5c07ce079de16..a878f44a106e6 100644
--- a/ext/xml/config.m4
+++ b/ext/xml/config.m4
@@ -31,7 +31,7 @@ if test "$PHP_XML" != "no"; then
   fi
 
   PHP_NEW_EXTENSION(xml, xml.c $xml_extra_sources, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1)
-  PHP_SUBST(XML_SHARED_LIBADD)
+  PHP_SUBST([XML_SHARED_LIBADD])
   PHP_INSTALL_HEADERS([ext/xml], [expat_compat.h php_xml.h])
   AC_DEFINE(HAVE_XML, 1, [ ])
 fi
diff --git a/ext/xmlreader/config.m4 b/ext/xmlreader/config.m4
index f3adc868e309f..793800659bbb4 100644
--- a/ext/xmlreader/config.m4
+++ b/ext/xmlreader/config.m4
@@ -10,6 +10,6 @@ if test "$PHP_XMLREADER" != "no"; then
     PHP_NEW_EXTENSION(xmlreader, php_xmlreader.c, $ext_shared)
     PHP_ADD_EXTENSION_DEP(xmlreader, dom, true)
     PHP_ADD_EXTENSION_DEP(xmlreader, libxml)
-    PHP_SUBST(XMLREADER_SHARED_LIBADD)
+    PHP_SUBST([XMLREADER_SHARED_LIBADD])
   ])
 fi
diff --git a/ext/xmlwriter/config.m4 b/ext/xmlwriter/config.m4
index a969548a42bdc..2c6e1e60152d9 100644
--- a/ext/xmlwriter/config.m4
+++ b/ext/xmlwriter/config.m4
@@ -9,6 +9,6 @@ if test "$PHP_XMLWRITER" != "no"; then
     AC_DEFINE(HAVE_XMLWRITER,1,[ ])
     PHP_NEW_EXTENSION(xmlwriter, php_xmlwriter.c, $ext_shared)
     PHP_ADD_EXTENSION_DEP(xmlwriter, libxml)
-    PHP_SUBST(XMLWRITER_SHARED_LIBADD)
+    PHP_SUBST([XMLWRITER_SHARED_LIBADD])
   ])
 fi
diff --git a/ext/xsl/config.m4 b/ext/xsl/config.m4
index 8d45e8eacb9a3..99674eccca42b 100644
--- a/ext/xsl/config.m4
+++ b/ext/xsl/config.m4
@@ -27,7 +27,7 @@ if test "$PHP_XSL" != "no"; then
 
   AC_DEFINE(HAVE_XSL,1,[ ])
   PHP_NEW_EXTENSION(xsl, php_xsl.c xsltprocessor.c, $ext_shared)
-  PHP_SUBST(XSL_SHARED_LIBADD)
+  PHP_SUBST([XSL_SHARED_LIBADD])
   PHP_ADD_EXTENSION_DEP(xsl, libxml)
   PHP_ADD_EXTENSION_DEP(xsl, dom)
 fi
diff --git a/ext/zip/config.m4 b/ext/zip/config.m4
index f8e088aa4f1a7..7c15d5321103b 100644
--- a/ext/zip/config.m4
+++ b/ext/zip/config.m4
@@ -65,5 +65,5 @@ if test "$PHP_ZIP" != "no"; then
   PHP_NEW_EXTENSION(zip, $PHP_ZIP_SOURCES, $ext_shared)
   PHP_ADD_EXTENSION_DEP(zip, pcre)
 
-  PHP_SUBST(ZIP_SHARED_LIBADD)
+  PHP_SUBST([ZIP_SHARED_LIBADD])
 fi