diff --git a/src/util/StringUtil.cxx b/src/util/StringUtil.cxx
index 872fa70d8..5b5ca8663 100644
--- a/src/util/StringUtil.cxx
+++ b/src/util/StringUtil.cxx
@@ -18,35 +18,19 @@
  */
 
 #include "StringUtil.hxx"
-#include "StringView.hxx"
+#include "StringCompare.hxx"
 #include "CharUtil.hxx"
-#include "ASCII.hxx"
 
 #include <cassert>
 
 bool
 StringArrayContainsCase(const char *const*haystack,
-			const char *needle) noexcept
+			std::string_view needle) noexcept
 {
 	assert(haystack != nullptr);
-	assert(needle != nullptr);
 
 	for (; *haystack != nullptr; ++haystack)
-		if (StringEqualsCaseASCII(*haystack, needle))
-			return true;
-
-	return false;
-}
-
-bool
-StringArrayContainsCase(const char *const*haystack,
-			StringView needle) noexcept
-{
-	assert(haystack != nullptr);
-	assert(needle != nullptr);
-
-	for (; *haystack != nullptr; ++haystack)
-		if (needle.EqualsIgnoreCase(*haystack))
+		if (StringIsEqualIgnoreCase(*haystack, needle))
 			return true;
 
 	return false;
diff --git a/src/util/StringUtil.hxx b/src/util/StringUtil.hxx
index 17c892433..3b599564c 100644
--- a/src/util/StringUtil.hxx
+++ b/src/util/StringUtil.hxx
@@ -23,8 +23,7 @@
 #include "Compiler.h"
 
 #include <cstddef>
-
-struct StringView;
+#include <string_view>
 
 /**
  * Checks whether a string array contains the specified string.
@@ -37,12 +36,7 @@ struct StringView;
 gcc_pure
 bool
 StringArrayContainsCase(const char *const*haystack,
-			const char *needle) noexcept;
-
-gcc_pure
-bool
-StringArrayContainsCase(const char *const*haystack,
-			StringView needle) noexcept;
+			std::string_view needle) noexcept;
 
 /**
  * Convert the specified ASCII string (0x00..0x7f) to upper case.