diff --git a/Zend/tests/inheritance/argument_restriction_001.phpt b/Zend/tests/inheritance/argument_restriction_001.phpt
index 2c54636a5817..6eb3ff8d2706 100644
--- a/Zend/tests/inheritance/argument_restriction_001.phpt
+++ b/Zend/tests/inheritance/argument_restriction_001.phpt
@@ -13,4 +13,4 @@ class Sub extends Base {
 }
 ?>
 --EXPECTF--
-Fatal error: Declaration of & Sub::test() must be compatible with & Base::test($foo, array $bar, $option = null, $extra = 'llllllllll...') in %s on line %d
+Fatal error: Declaration of &Sub::test() must be compatible with &Base::test($foo, array $bar, $option = null, $extra = 'llllllllll...') in %s on line %d
diff --git a/Zend/tests/objects/objects_005.phpt b/Zend/tests/objects/objects_005.phpt
index 9b9a41465f95..7749a39d986f 100644
--- a/Zend/tests/objects/objects_005.phpt
+++ b/Zend/tests/objects/objects_005.phpt
@@ -19,4 +19,4 @@ class test3 extends test {
 
 ?>
 --EXPECTF--
-Fatal error: Declaration of test3::foo() must be compatible with & test::foo() in %s on line %d
+Fatal error: Declaration of test3::foo() must be compatible with &test::foo() in %s on line %d
diff --git a/Zend/tests/property_hooks/get_by_ref_implemented_by_val.phpt b/Zend/tests/property_hooks/get_by_ref_implemented_by_val.phpt
index 84eb96826354..2c507d862be6 100644
--- a/Zend/tests/property_hooks/get_by_ref_implemented_by_val.phpt
+++ b/Zend/tests/property_hooks/get_by_ref_implemented_by_val.phpt
@@ -15,4 +15,4 @@ class A implements I {
 
 ?>
 --EXPECTF--
-Fatal error: Declaration of A::$prop::get() must be compatible with & I::$prop::get() in %s on line %d
+Fatal error: Declaration of A::$prop::get() must be compatible with &I::$prop::get() in %s on line %d
diff --git a/Zend/zend_inheritance.c b/Zend/zend_inheritance.c
index a2da64b62c0d..1f128764bdd3 100644
--- a/Zend/zend_inheritance.c
+++ b/Zend/zend_inheritance.c
@@ -916,7 +916,7 @@ static ZEND_COLD zend_string *zend_get_function_declaration(
 	smart_str str = {0};
 
 	if (fptr->op_array.fn_flags & ZEND_ACC_RETURN_REFERENCE) {
-		smart_str_appends(&str, "& ");
+		smart_str_appendc(&str, '&');
 	}
 
 	if (fptr->common.scope) {
diff --git a/ext/tidy/config.m4 b/ext/tidy/config.m4
index 55474d7d951d..ef1f5878287d 100644
--- a/ext/tidy/config.m4
+++ b/ext/tidy/config.m4
@@ -57,19 +57,34 @@ if test "$PHP_TIDY" != "no"; then
     [],
     [-L$TIDY_LIBDIR])
 
-  dnl The tidyOptGetCategory function (added in libtidy 5.4.0) if only useable
-  dnl if TidyInternalCategory (added in libtidy 5.6.0) is also present.
-  PHP_CHECK_LIBRARY([$TIDY_LIB_NAME], [tidyInternalCategory],
-    [AC_DEFINE([HAVE_TIDYOPTGETCATEGORY], [1],
-      [Define to 1 if Tidy library has the 'tidyOptGetCategory' function.])],
-    [],
-    [-L$TIDY_LIBDIR])
-
   PHP_ADD_LIBRARY_WITH_PATH([$TIDY_LIB_NAME],
     [$TIDY_LIBDIR],
     [TIDY_SHARED_LIBADD])
   PHP_ADD_INCLUDE([$TIDY_INCDIR])
 
+  old_CPPFLAGS=$CPPFLAGS
+  CPPFLAGS=-I$TIDY_INCDIR
+
+  dnl The tidyOptGetCategory function (added in tidy-html5 5.4.0) is only
+  dnl useable if TidyInternalCategory (added in tidy-html5 5.6.0) is also
+  dnl present.
+  AC_CACHE_CHECK([for tidyOptGetCategory], [php_ac_cv_have_tidyoptgetcategory],
+  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <tidy.h>],[
+     TidyDoc doc = tidyCreate();
+     TidyOption badopt = tidyGetOptionByName(doc, "<bad>");
+     Bool v = (tidyOptGetCategory(badopt) == TidyInternalCategory);
+     (void)v;
+     tidyRelease(doc);
+    ])],
+    [php_ac_cv_have_tidyoptgetcategory=yes],
+    [php_ac_cv_have_tidyoptgetcategory=no])
+  ])
+  AS_VAR_IF([php_ac_cv_have_tidyoptgetcategory], [yes],
+    [AC_DEFINE([HAVE_TIDYOPTGETCATEGORY], [1],
+      [Define to 1 if tidyOptGetCategory is available.])])
+
+  CPPFLAGS=$old_CPPFLAGS
+
   dnl Add -Wno-ignored-qualifiers as this is an issue upstream. Fixed in
   dnl tidy-html5 5.7.20: https://github.com/htacg/tidy-html5/issues/866
   PHP_NEW_EXTENSION([tidy],