diff --git a/kandinsky/Makefile b/kandinsky/Makefile
index af4804052..368948437 100644
--- a/kandinsky/Makefile
+++ b/kandinsky/Makefile
@@ -13,7 +13,7 @@ src += $(addprefix kandinsky/src/,\
   ion_context.cpp \
   point.cpp \
   rect.cpp \
-  unicode/utf8decoder.cpp\
+  unicode/utf8_decoder.cpp\
 )
 
 src += $(addprefix kandinsky/fonts/, \
@@ -25,7 +25,7 @@ tests += $(addprefix kandinsky/test/,\
   color.cpp\
   font.cpp\
   rect.cpp\
-  utf8decoder.cpp\
+  utf8_decoder.cpp\
 )
 
 RASTERIZER_CFLAGS := -std=c99 `pkg-config freetype2 --cflags`
diff --git a/kandinsky/include/kandinsky/unicode/utf8decoder.h b/kandinsky/include/kandinsky/unicode/utf8_decoder.h
similarity index 90%
rename from kandinsky/include/kandinsky/unicode/utf8decoder.h
rename to kandinsky/include/kandinsky/unicode/utf8_decoder.h
index fcabe859a..f4dab5269 100644
--- a/kandinsky/include/kandinsky/unicode/utf8decoder.h
+++ b/kandinsky/include/kandinsky/unicode/utf8_decoder.h
@@ -1,5 +1,5 @@
-#ifndef KANDINSKY_UNICODE_UTF8DECODER_H
-#define KANDINSKY_UNICODE_UTF8DECODER_H
+#ifndef KANDINSKY_UNICODE_UTF8_DECODER_H
+#define KANDINSKY_UNICODE_UTF8_DECODER_H
 
 #include <stddef.h>
 #include "code_point.h"
diff --git a/kandinsky/src/context_text.cpp b/kandinsky/src/context_text.cpp
index 05728dbba..860d9da65 100644
--- a/kandinsky/src/context_text.cpp
+++ b/kandinsky/src/context_text.cpp
@@ -1,7 +1,7 @@
 #include <assert.h>
 #include <kandinsky/context.h>
 #include <kandinsky/font.h>
-#include <kandinsky/unicode/utf8decoder.h>
+#include <kandinsky/unicode/utf8_decoder.h>
 
 constexpr static int k_tabCharacterWidth = 4;
 
diff --git a/kandinsky/src/font.cpp b/kandinsky/src/font.cpp
index 6f48d7814..a921b4a4b 100644
--- a/kandinsky/src/font.cpp
+++ b/kandinsky/src/font.cpp
@@ -1,7 +1,7 @@
 #include <assert.h>
 #include <kandinsky/font.h>
 #include <ion.h>
-#include <kandinsky/unicode/utf8decoder.h>
+#include <kandinsky/unicode/utf8_decoder.h>
 
 constexpr static int k_tabCharacterWidth = 4;
 
diff --git a/kandinsky/src/unicode/utf8decoder.cpp b/kandinsky/src/unicode/utf8_decoder.cpp
similarity index 96%
rename from kandinsky/src/unicode/utf8decoder.cpp
rename to kandinsky/src/unicode/utf8_decoder.cpp
index 5648df4df..bdb6ed370 100644
--- a/kandinsky/src/unicode/utf8decoder.cpp
+++ b/kandinsky/src/unicode/utf8_decoder.cpp
@@ -1,4 +1,4 @@
-#include <kandinsky/unicode/utf8decoder.h>
+#include <kandinsky/unicode/utf8_decoder.h>
 #include <assert.h>
 
 static inline int leading_ones(uint8_t value) {
diff --git a/kandinsky/test/utf8decoder.cpp b/kandinsky/test/utf8decoder.cpp
index 1198166a6..3c649f3b7 100644
--- a/kandinsky/test/utf8decoder.cpp
+++ b/kandinsky/test/utf8decoder.cpp
@@ -1,5 +1,5 @@
 #include <quiz.h>
-#include <kandinsky/unicode/utf8decoder.h>
+#include <kandinsky/unicode/utf8_decoder.h>
 
 void assert_decodes_to(const char * string, CodePoint c) {
   UTF8Decoder d(string);
diff --git a/poincare/src/parsing/tokenizer.cpp b/poincare/src/parsing/tokenizer.cpp
index 0dfa5e0fa..9b7d440f7 100644
--- a/poincare/src/parsing/tokenizer.cpp
+++ b/poincare/src/parsing/tokenizer.cpp
@@ -1,7 +1,7 @@
 #include "tokenizer.h"
 #include <ion/charset.h>
 #include <poincare/number.h>
-#include <kandinsky/unicode/utf8decoder.h>
+#include <kandinsky/unicode/utf8_decoder.h>
 
 namespace Poincare {