diff --git a/Source/UnitTests/Common/StringUtilTest.cpp b/Source/UnitTests/Common/StringUtilTest.cpp
index 28bd150c06..59ba99a436 100644
--- a/Source/UnitTests/Common/StringUtilTest.cpp
+++ b/Source/UnitTests/Common/StringUtilTest.cpp
@@ -2,10 +2,12 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <gtest/gtest.h>
+
 #include <string>
 #include <vector>
 
 #include "Common/StringUtil.h"
+#include "Common/Swap.h"
 
 TEST(StringUtil, StringPopBackIf)
 {
@@ -256,3 +258,26 @@ TEST(StringUtil, CaseInsensitiveContains_OverlappingMatches)
   EXPECT_TRUE(Common::CaseInsensitiveContains("aaaaaa", "aa"));
   EXPECT_TRUE(Common::CaseInsensitiveContains("ababababa", "bABa"));
 }
+
+TEST(StringUtil, CharacterEncodingConversion)
+{
+  // wstring
+  EXPECT_EQ(WStringToUTF8(L"hello 🐬"), "hello 🐬");
+
+  // UTF-16
+  EXPECT_EQ(UTF16ToUTF8(u"hello 🐬"), "hello 🐬");
+  EXPECT_EQ(UTF8ToUTF16("hello 🐬"), u"hello 🐬");
+
+  // UTF-16BE
+  char16_t utf16be_str[] = u"hello 🐬";
+  for (auto& c : utf16be_str)
+    c = Common::swap16(c);
+  EXPECT_EQ(UTF16BEToUTF8(utf16be_str, 99), "hello 🐬");
+
+  // Shift JIS
+  EXPECT_EQ(SHIFTJISToUTF8("\x83\x43\x83\x8b\x83\x4a"), "イルカ");
+  EXPECT_EQ(UTF8ToSHIFTJIS("イルカ"), "\x83\x43\x83\x8b\x83\x4a");
+
+  // CP1252
+  EXPECT_EQ(CP1252ToUTF8("hello \xa5"), "hello ¥");
+}