diff --git a/src/util/NumberParser.cxx b/src/util/NumberParser.cxx
index 995e9f9ca..b9d796dbb 100644
--- a/src/util/NumberParser.cxx
+++ b/src/util/NumberParser.cxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2019 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2009-2022 Max Kellermann <max.kellermann@gmail.com>
  * http://www.musicpd.org
  *
  * Redistribution and use in source and binary forms, with or without
@@ -29,22 +29,21 @@
  */
 
 #include "NumberParser.hxx"
-#include "StringView.hxx"
 
 #include <algorithm>
 #include <iterator>
 
 int64_t
-ParseInt64(StringView s, const char **endptr_r, int base) noexcept
+ParseInt64(std::string_view s, const char **endptr_r, int base) noexcept
 {
 	char buffer[32];
-	*std::copy_n(s.data, std::min(s.size, std::size(buffer) - 1),
+	*std::copy_n(s.data(), std::min(s.size(), std::size(buffer) - 1),
 		     buffer) = 0;
 
 	char *endptr;
 	const auto result = ParseInt64(buffer, &endptr, base);
 	if (endptr_r != nullptr)
-		*endptr_r = s.data + (endptr - buffer);
+		*endptr_r = s.data() + (endptr - buffer);
 
 	return result;
 }
diff --git a/src/util/NumberParser.hxx b/src/util/NumberParser.hxx
index d0ecbd061..dd65ffe68 100644
--- a/src/util/NumberParser.hxx
+++ b/src/util/NumberParser.hxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2019 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2009-2022 Max Kellermann <max.kellermann@gmail.com>
  * http://www.musicpd.org
  *
  * Redistribution and use in source and binary forms, with or without
@@ -28,16 +28,14 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef NUMBER_PARSER_HXX
-#define NUMBER_PARSER_HXX
+#pragma once
 
 #include <cassert>
 #include <cstdint>
+#include <string_view>
 
 #include <stdlib.h>
 
-struct StringView;
-
 static inline unsigned
 ParseUnsigned(const char *p, char **endptr=nullptr, int base=10) noexcept
 {
@@ -71,7 +69,7 @@ ParseInt64(const char *p, char **endptr=nullptr, int base=10) noexcept
 }
 
 int64_t
-ParseInt64(StringView s, const char **endptr_r=nullptr, int base=10) noexcept;
+ParseInt64(std::string_view s, const char **endptr_r=nullptr, int base=10) noexcept;
 
 static inline double
 ParseDouble(const char *p, char **endptr=nullptr) noexcept
@@ -91,5 +89,3 @@ ParseFloat(const char *p, char **endptr=nullptr) noexcept
 	return strtof(p, endptr);
 #endif
 }
-
-#endif