diff --git a/src/filter/plugins/NormalizeFilterPlugin.cxx b/src/filter/plugins/NormalizeFilterPlugin.cxx
index f6db758ee..2b501fb5c 100644
--- a/src/filter/plugins/NormalizeFilterPlugin.cxx
+++ b/src/filter/plugins/NormalizeFilterPlugin.cxx
@@ -7,7 +7,7 @@
 #include "filter/Prepared.hxx"
 #include "pcm/Buffer.hxx"
 #include "pcm/AudioFormat.hxx"
-#include "pcm/AudioCompress/compress.h"
+#include "pcm/Normalizer.hxx"
 
 #include <string.h>
 
diff --git a/src/pcm/AudioCompress/compress.c b/src/pcm/Normalizer.cxx
similarity index 92%
rename from src/pcm/AudioCompress/compress.c
rename to src/pcm/Normalizer.cxx
index e46e4a9a7..1dbf40d57 100644
--- a/src/pcm/AudioCompress/compress.c
+++ b/src/pcm/Normalizer.cxx
@@ -1,13 +1,14 @@
 // SPDX-License-Identifier: LGPL-2.1
-// (c)2007 busybee (http://beesbuzz.biz/
+// Copyright The Music Player Daemon Project
+// Based on AudioCompress (c)2007 busybee (http://beesbuzz.biz/
+
+#include "Normalizer.hxx"
 
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
-#include "compress.h"
-
 /*** Default configuration stuff ***/
 #define TARGET 16384		/*!< Target level (on a scale of 0-32767) */
 
@@ -34,8 +35,8 @@ struct Compressor {
 
 struct Compressor *Compressor_new(unsigned int history)
 {
-	struct Compressor *obj = malloc(sizeof(struct Compressor));
-	if (obj == NULL)
+	Compressor *obj = (Compressor *)malloc(sizeof(struct Compressor));
+	if (obj == nullptr)
 		/* out of memory, not much we can do */
 		abort();
 
@@ -43,7 +44,7 @@ struct Compressor *Compressor_new(unsigned int history)
 	obj->prefs.maxgain = GAINMAX;
 	obj->prefs.smooth = GAINSMOOTH;
 
-        obj->peaks = obj->gain = obj->clipped = NULL;
+        obj->peaks = obj->gain = obj->clipped = nullptr;
 	obj->bufsz = 0;
         obj->pos = 0;
 
@@ -65,8 +66,8 @@ void Compressor_delete(struct Compressor *obj)
 
 static int *resizeArray(int *data, int newsz, int oldsz)
 {
-        data = realloc(data, newsz*sizeof(int));
-	if (data == NULL)
+        data = (int *)realloc(data, newsz*sizeof(int));
+	if (data == nullptr)
 		/* out of memory, not much we can do */
 		abort();
 
diff --git a/src/pcm/AudioCompress/compress.h b/src/pcm/Normalizer.hxx
similarity index 83%
rename from src/pcm/AudioCompress/compress.h
rename to src/pcm/Normalizer.hxx
index 4144e5dac..2e0d14d56 100644
--- a/src/pcm/AudioCompress/compress.h
+++ b/src/pcm/Normalizer.hxx
@@ -1,10 +1,10 @@
 // SPDX-License-Identifier: LGPL-2.1
-// (c)2007 busybee (http://beesbuzz.biz/
+// Copyright The Music Player Daemon Project
+// Based on AudioCompress (c)2007 busybee (http://beesbuzz.biz/
 
-#ifndef COMPRESS_H
-#define COMPRESS_H
+#pragma once
 
-#include <stdint.h>
+#include <cstdint>
 
 //! Configuration values for the compressor object
 struct CompressorConfig {
@@ -15,10 +15,6 @@ struct CompressorConfig {
 
 struct Compressor;
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 //! Create a new compressor (use history value of 0 for default)
 struct Compressor *Compressor_new(unsigned int history);
 
@@ -34,12 +30,6 @@ struct CompressorConfig *Compressor_getConfig(struct Compressor *);
 //! Process 16-bit signed data
 void Compressor_Process_int16(struct Compressor *, int16_t *data, unsigned int count);
 
-#ifdef __cplusplus
-}
-#endif
-
 //! TODO: Compressor_Process_int32, Compressor_Process_float, others as needed
 
 //! TODO: functions for getting at the peak/gain/clip history buffers (for monitoring)
-
-#endif
diff --git a/src/pcm/meson.build b/src/pcm/meson.build
index 59d73d59e..0c769c4e7 100644
--- a/src/pcm/meson.build
+++ b/src/pcm/meson.build
@@ -47,7 +47,7 @@ pcm_sources = [
   'GlueResampler.cxx',
   'FallbackResampler.cxx',
   'ConfiguredResampler.cxx',
-  'AudioCompress/compress.c',
+  'Normalizer.cxx',
   'ReplayGainAnalyzer.cxx',
   'MixRampAnalyzer.cxx',
   'MixRampGlue.cxx',
diff --git a/test/run_normalize.cxx b/test/run_normalize.cxx
index f70a6ea9e..4145a96d7 100644
--- a/test/run_normalize.cxx
+++ b/test/run_normalize.cxx
@@ -7,7 +7,7 @@
  *
  */
 
-#include "pcm/AudioCompress/compress.h"
+#include "pcm/Normalizer.hxx"
 #include "pcm/AudioParser.hxx"
 #include "pcm/AudioFormat.hxx"
 #include "util/PrintException.hxx"