diff --git a/core/fxcodec/BUILD.gn b/core/fxcodec/BUILD.gn
index 70e71b7..63d4059 100644
--- a/core/fxcodec/BUILD.gn
+++ b/core/fxcodec/BUILD.gn
@@ -84,9 +84,9 @@
     sources += [
       "jpeg/jpeg_progressive_decoder.cpp",
       "jpeg/jpeg_progressive_decoder.h",
+      "progressive_decoder.cpp",
+      "progressive_decoder.h",
       "progressive_decoder_iface.h",
-      "progressivedecoder.cpp",
-      "progressivedecoder.h",
     ]
     if (pdf_enable_xfa_bmp) {
       sources += [
@@ -149,7 +149,7 @@
   pdfium_root_dir = "../../"
 
   if (pdf_enable_xfa) {
-    sources += [ "progressivedecoder_unittest.cpp" ]
+    sources += [ "progressive_decoder_unittest.cpp" ]
     deps += [ "../fxge" ]
     if (pdf_enable_xfa_gif) {
       sources += [
diff --git a/core/fxcodec/progressivedecoder.cpp b/core/fxcodec/progressive_decoder.cpp
similarity index 99%
rename from core/fxcodec/progressivedecoder.cpp
rename to core/fxcodec/progressive_decoder.cpp
index dd30428..fb36d6f 100644
--- a/core/fxcodec/progressivedecoder.cpp
+++ b/core/fxcodec/progressive_decoder.cpp
@@ -4,7 +4,7 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#include "core/fxcodec/progressivedecoder.h"
+#include "core/fxcodec/progressive_decoder.h"
 
 #include <algorithm>
 #include <memory>
diff --git a/core/fxcodec/progressivedecoder.h b/core/fxcodec/progressive_decoder.h
similarity index 98%
rename from core/fxcodec/progressivedecoder.h
rename to core/fxcodec/progressive_decoder.h
index 10debd1..05547a3 100644
--- a/core/fxcodec/progressivedecoder.h
+++ b/core/fxcodec/progressive_decoder.h
@@ -4,8 +4,8 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#ifndef CORE_FXCODEC_PROGRESSIVEDECODER_H_
-#define CORE_FXCODEC_PROGRESSIVEDECODER_H_
+#ifndef CORE_FXCODEC_PROGRESSIVE_DECODER_H_
+#define CORE_FXCODEC_PROGRESSIVE_DECODER_H_
 
 #include <memory>
 #include <utility>
@@ -296,4 +296,4 @@
 
 using ProgressiveDecoder = fxcodec::ProgressiveDecoder;
 
-#endif  // CORE_FXCODEC_PROGRESSIVEDECODER_H_
+#endif  // CORE_FXCODEC_PROGRESSIVE_DECODER_H_
diff --git a/core/fxcodec/progressivedecoder_unittest.cpp b/core/fxcodec/progressive_decoder_unittest.cpp
similarity index 99%
rename from core/fxcodec/progressivedecoder_unittest.cpp
rename to core/fxcodec/progressive_decoder_unittest.cpp
index f756f5e..9ace0d0 100644
--- a/core/fxcodec/progressivedecoder_unittest.cpp
+++ b/core/fxcodec/progressive_decoder_unittest.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "core/fxcodec/progressivedecoder.h"
+#include "core/fxcodec/progressive_decoder.h"
 
 #include "core/fxcodec/fx_codec.h"
 #include "core/fxcrt/cfx_readonlymemorystream.h"
diff --git a/testing/fuzzers/xfa_codec_fuzzer.h b/testing/fuzzers/xfa_codec_fuzzer.h
index ef9ce69..285259e 100644
--- a/testing/fuzzers/xfa_codec_fuzzer.h
+++ b/testing/fuzzers/xfa_codec_fuzzer.h
@@ -8,7 +8,7 @@
 #include <memory>
 
 #include "core/fxcodec/fx_codec.h"
-#include "core/fxcodec/progressivedecoder.h"
+#include "core/fxcodec/progressive_decoder.h"
 #include "core/fxcrt/cfx_readonlymemorystream.h"
 #include "core/fxcrt/retain_ptr.h"
 #include "core/fxge/dib/cfx_dibitmap.h"
diff --git a/xfa/fxfa/cxfa_ffwidget.cpp b/xfa/fxfa/cxfa_ffwidget.cpp
index 2515454..47086e0 100644
--- a/xfa/fxfa/cxfa_ffwidget.cpp
+++ b/xfa/fxfa/cxfa_ffwidget.cpp
@@ -13,7 +13,7 @@
 #include <vector>
 
 #include "core/fxcodec/fx_codec.h"
-#include "core/fxcodec/progressivedecoder.h"
+#include "core/fxcodec/progressive_decoder.h"
 #include "core/fxcrt/maybe_owned.h"
 #include "core/fxge/cfx_pathdata.h"
 #include "core/fxge/cfx_renderdevice.h"