diff --git a/src/archive/ArchiveList.cxx b/src/archive/ArchiveList.cxx
index 25a4a72f9..c45daf15d 100644
--- a/src/archive/ArchiveList.cxx
+++ b/src/archive/ArchiveList.cxx
@@ -55,10 +55,8 @@ static bool archive_plugins_enabled[std::max(n_archive_plugins, std::size_t(1))]
 		if (archive_plugins_enabled[archive_plugin_iterator - archive_plugins])
 
 const ArchivePlugin *
-archive_plugin_from_suffix(const char *suffix) noexcept
+archive_plugin_from_suffix(std::string_view suffix) noexcept
 {
-	assert(suffix != nullptr);
-
 	archive_plugins_for_each_enabled(plugin)
 		if (plugin->suffixes != nullptr &&
 		    StringArrayContainsCase(plugin->suffixes, suffix))
diff --git a/src/archive/ArchiveList.hxx b/src/archive/ArchiveList.hxx
index 5a0a7925f..198c400fc 100644
--- a/src/archive/ArchiveList.hxx
+++ b/src/archive/ArchiveList.hxx
@@ -20,6 +20,8 @@
 #ifndef MPD_ARCHIVE_LIST_HXX
 #define MPD_ARCHIVE_LIST_HXX
 
+#include <string_view>
+
 struct ArchivePlugin;
 
 extern const ArchivePlugin *const archive_plugins[];
@@ -33,7 +35,7 @@ extern const ArchivePlugin *const archive_plugins[];
 /* interface for using plugins */
 
 const ArchivePlugin *
-archive_plugin_from_suffix(const char *suffix) noexcept;
+archive_plugin_from_suffix(std::string_view suffix) noexcept;
 
 const ArchivePlugin *
 archive_plugin_from_name(const char *name) noexcept;
diff --git a/src/command/FingerprintCommands.cxx b/src/command/FingerprintCommands.cxx
index 5a4ef5b51..d75b9f5be 100644
--- a/src/command/FingerprintCommands.cxx
+++ b/src/command/FingerprintCommands.cxx
@@ -124,7 +124,7 @@ decoder_check_plugin_mime(const DecoderPlugin &plugin,
 
 	const char *mime_type = is.GetMimeType();
 	return mime_type != nullptr &&
-		plugin.SupportsMimeType(GetMimeTypeBase(mime_type).c_str());
+		plugin.SupportsMimeType(GetMimeTypeBase(mime_type));
 }
 
 gcc_pure
diff --git a/src/decoder/DecoderList.cxx b/src/decoder/DecoderList.cxx
index 7bca4b0d7..1d6640759 100644
--- a/src/decoder/DecoderList.cxx
+++ b/src/decoder/DecoderList.cxx
@@ -175,7 +175,7 @@ decoder_plugin_deinit_all() noexcept
 }
 
 bool
-decoder_plugins_supports_suffix(const char *suffix) noexcept
+decoder_plugins_supports_suffix(std::string_view suffix) noexcept
 {
 	return decoder_plugins_try([suffix](const DecoderPlugin &plugin){
 			return plugin.SupportsSuffix(suffix);
diff --git a/src/decoder/DecoderList.hxx b/src/decoder/DecoderList.hxx
index f3ec3c153..ecb453a03 100644
--- a/src/decoder/DecoderList.hxx
+++ b/src/decoder/DecoderList.hxx
@@ -22,6 +22,8 @@
 
 #include "util/Compiler.h"
 
+#include <string_view>
+
 struct ConfigData;
 struct DecoderPlugin;
 
@@ -98,6 +100,6 @@ decoder_plugins_for_each_enabled(F f)
  */
 gcc_pure gcc_nonnull_all
 bool
-decoder_plugins_supports_suffix(const char *suffix) noexcept;
+decoder_plugins_supports_suffix(std::string_view suffix) noexcept;
 
 #endif
diff --git a/src/decoder/DecoderPlugin.cxx b/src/decoder/DecoderPlugin.cxx
index bbb3966fc..e1ed4f513 100644
--- a/src/decoder/DecoderPlugin.cxx
+++ b/src/decoder/DecoderPlugin.cxx
@@ -37,25 +37,15 @@ DecoderPlugin::SupportsUri(const char *uri) const noexcept
 }
 
 bool
-DecoderPlugin::SupportsSuffix(const char *suffix) const noexcept
+DecoderPlugin::SupportsSuffix(std::string_view suffix) const noexcept
 {
-#if !CLANG_CHECK_VERSION(3,6)
-	/* disabled on clang due to -Wtautological-pointer-compare */
-	assert(suffix != nullptr);
-#endif
-
 	return suffixes != nullptr &&
 		StringArrayContainsCase(suffixes, suffix);
 }
 
 bool
-DecoderPlugin::SupportsMimeType(const char *mime_type) const noexcept
+DecoderPlugin::SupportsMimeType(std::string_view mime_type) const noexcept
 {
-#if !CLANG_CHECK_VERSION(3,6)
-	/* disabled on clang due to -Wtautological-pointer-compare */
-	assert(mime_type != nullptr);
-#endif
-
 	return mime_types != nullptr &&
 		StringArrayContainsCase(mime_types, mime_type);
 }
diff --git a/src/decoder/DecoderPlugin.hxx b/src/decoder/DecoderPlugin.hxx
index c09aa5032..674565dd5 100644
--- a/src/decoder/DecoderPlugin.hxx
+++ b/src/decoder/DecoderPlugin.hxx
@@ -25,6 +25,7 @@
 #include <forward_list>  // IWYU pragma: export
 #include <set>
 #include <string>
+#include <string_view>
 
 struct ConfigBlock;
 class InputStream;
@@ -252,15 +253,15 @@ struct DecoderPlugin {
 	 * Does the plugin announce the specified file name suffix?
 	 */
 	gcc_pure gcc_nonnull_all
-	bool SupportsSuffix(const char *suffix) const noexcept;
+	bool SupportsSuffix(std::string_view suffix) const noexcept;
 
 	/**
 	 * Does the plugin announce the specified MIME type?
 	 */
 	gcc_pure gcc_nonnull_all
-	bool SupportsMimeType(const char *mime_type) const noexcept;
+	bool SupportsMimeType(std::string_view mime_type) const noexcept;
 
-	bool SupportsContainerSuffix(const char *suffix) const noexcept {
+	bool SupportsContainerSuffix(std::string_view suffix) const noexcept {
 		return container_scan != nullptr && SupportsSuffix(suffix);
 	}
 };
diff --git a/src/decoder/Thread.cxx b/src/decoder/Thread.cxx
index d4d85edb4..00113063d 100644
--- a/src/decoder/Thread.cxx
+++ b/src/decoder/Thread.cxx
@@ -172,7 +172,7 @@ decoder_check_plugin_mime(const DecoderPlugin &plugin,
 
 	const char *mime_type = is.GetMimeType();
 	return mime_type != nullptr &&
-		plugin.SupportsMimeType(GetMimeTypeBase(mime_type).c_str());
+		plugin.SupportsMimeType(GetMimeTypeBase(mime_type));
 }
 
 gcc_pure
diff --git a/src/playlist/PlaylistPlugin.cxx b/src/playlist/PlaylistPlugin.cxx
index ad01ba393..a243316b8 100644
--- a/src/playlist/PlaylistPlugin.cxx
+++ b/src/playlist/PlaylistPlugin.cxx
@@ -29,7 +29,7 @@ PlaylistPlugin::SupportsScheme(StringView scheme) const noexcept
 }
 
 bool
-PlaylistPlugin::SupportsSuffix(const char *suffix) const noexcept
+PlaylistPlugin::SupportsSuffix(StringView suffix) const noexcept
 {
 	return suffixes != nullptr &&
 		StringArrayContainsCase(suffixes, suffix);
diff --git a/src/playlist/PlaylistPlugin.hxx b/src/playlist/PlaylistPlugin.hxx
index d729296e1..8740a13a7 100644
--- a/src/playlist/PlaylistPlugin.hxx
+++ b/src/playlist/PlaylistPlugin.hxx
@@ -126,7 +126,7 @@ struct PlaylistPlugin {
 	 * Does the plugin announce the specified file name suffix?
 	 */
 	gcc_pure gcc_nonnull_all
-	bool SupportsSuffix(const char *suffix) const noexcept;
+	bool SupportsSuffix(StringView suffix) const noexcept;
 
 	/**
 	 * Does the plugin announce the specified MIME type?
diff --git a/src/playlist/PlaylistRegistry.cxx b/src/playlist/PlaylistRegistry.cxx
index b9f6bb7ec..54540b5e4 100644
--- a/src/playlist/PlaylistRegistry.cxx
+++ b/src/playlist/PlaylistRegistry.cxx
@@ -238,10 +238,8 @@ playlist_list_open_stream_mime(InputStreamPtr &&is, const char *full_mime)
 }
 
 std::unique_ptr<SongEnumerator>
-playlist_list_open_stream_suffix(InputStreamPtr &&is, const char *suffix)
+playlist_list_open_stream_suffix(InputStreamPtr &&is, std::string_view suffix)
 {
-	assert(suffix != nullptr);
-
 	playlist_plugins_for_each_enabled(plugin) {
 		if (plugin->open_stream != nullptr &&
 		    plugin->SupportsSuffix(suffix)) {
@@ -289,10 +287,8 @@ playlist_list_open_stream(InputStreamPtr &&is, const char *uri)
 }
 
 const PlaylistPlugin *
-FindPlaylistPluginBySuffix(const char *suffix) noexcept
+FindPlaylistPluginBySuffix(std::string_view suffix) noexcept
 {
-	assert(suffix != nullptr);
-
 	playlist_plugins_for_each_enabled(plugin) {
 		if (plugin->SupportsSuffix(suffix))
 			return plugin;
diff --git a/src/playlist/PlaylistRegistry.hxx b/src/playlist/PlaylistRegistry.hxx
index 205fbb4b2..ea036cc5d 100644
--- a/src/playlist/PlaylistRegistry.hxx
+++ b/src/playlist/PlaylistRegistry.hxx
@@ -24,6 +24,8 @@
 #include "thread/Mutex.hxx"
 #include "util/Compiler.h"
 
+#include <string_view>
+
 struct ConfigData;
 struct PlaylistPlugin;
 class SongEnumerator;
@@ -74,7 +76,7 @@ std::unique_ptr<SongEnumerator>
 playlist_list_open_uri(const char *uri, Mutex &mutex);
 
 std::unique_ptr<SongEnumerator>
-playlist_list_open_stream_suffix(InputStreamPtr &&is, const char *suffix);
+playlist_list_open_stream_suffix(InputStreamPtr &&is, std::string_view suffix);
 
 /**
  * Opens a playlist from an input stream.
@@ -88,7 +90,7 @@ playlist_list_open_stream(InputStreamPtr &&is, const char *uri);
 
 gcc_pure
 const PlaylistPlugin *
-FindPlaylistPluginBySuffix(const char *suffix) noexcept;
+FindPlaylistPluginBySuffix(std::string_view suffix) noexcept;
 
 /**
  * Determines if there is a playlist plugin which can handle the
@@ -96,7 +98,7 @@ FindPlaylistPluginBySuffix(const char *suffix) noexcept;
  */
 gcc_pure
 inline bool
-playlist_suffix_supported(const char *suffix) noexcept
+playlist_suffix_supported(std::string_view suffix) noexcept
 {
 	return FindPlaylistPluginBySuffix(suffix) != nullptr;
 }
diff --git a/src/playlist/PlaylistStream.cxx b/src/playlist/PlaylistStream.cxx
index cebcc38e1..1867531d4 100644
--- a/src/playlist/PlaylistStream.cxx
+++ b/src/playlist/PlaylistStream.cxx
@@ -23,6 +23,7 @@
 #include "input/InputStream.hxx"
 #include "input/LocalOpen.hxx"
 #include "fs/Path.hxx"
+#include "util/StringView.hxx"
 #include "util/UriExtract.hxx"
 #include "Log.hxx"
 
@@ -39,12 +40,12 @@ try {
 		return nullptr;
 
 	const auto suffix_utf8 = Path::FromFS(suffix).ToUTF8Throw();
-	if (!playlist_suffix_supported(suffix_utf8.c_str()))
+	if (!playlist_suffix_supported(suffix_utf8))
 		return nullptr;
 
 	auto is = OpenLocalInputStream(path, mutex);
 	return playlist_list_open_stream_suffix(std::move(is),
-						suffix_utf8.c_str());
+						suffix_utf8);
 } catch (...) {
 	LogError(std::current_exception());
 	return nullptr;