diff --git a/CHANGELOG b/CHANGELOG
index d790eefc7..7820d3a4b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,8 @@
 0.83.21
   - Pausing the emulation will automatically release the
     mouse and prevent mouse capture. (Wengier)
+  - Improved IME support for CJK languages on the
+    Windows SDL2 builds. (Wengier)
   - The selected text will be highlighted when you try
     to select text for copying in J-3100 mode. (Wengier)
   - Config option "pixelshader" now allows a shader file
@@ -9,7 +11,9 @@
   - Added config options (in "ethernet, slirp" section)
     "tcp_port_forwards" and "tcp_port_forwards" for port
     forwarding when using the Slirp backend. (kcgen)
-  - Added hidden code page 951 for Big5-HKSCS. (Wengier)
+  - Added hidden code page 951 for Big5-HKSCS encoding.
+    If ChinaSea is enabled, ChinaSea characters will be
+    used instead of the original characters. (Wengier)
   - Mac OS X builds from now on will use an in-tree tool
     to replace dylib references in all executable files.
     XCode install_name_tool is no longer used, it became
diff --git a/src/dosbox.cpp b/src/dosbox.cpp
index 7d416a1f1..38a8f46e0 100644
--- a/src/dosbox.cpp
+++ b/src/dosbox.cpp
@@ -1102,6 +1102,9 @@ void DOSBOX_RealInit() {
     }
 #elif (defined(WIN32) && !defined(HX_DOS) || defined(LINUX) && C_X11) && defined(C_SDL2)
     if (enableime && !control->opt_silent) {
+#if !defined(SDL_DOSBOX_X_IME)
+        LOG_MSG("Note: The linked SDL 2.x library is not compiled with enhanced IME functions.")
+#endif
         dos.im_enable_flag = true;
         SDL_StartTextInput();
 #if defined(LINUX)
diff --git a/src/gui/sdlmain.cpp b/src/gui/sdlmain.cpp
index cfdbfa59f..cc400d364 100644
--- a/src/gui/sdlmain.cpp
+++ b/src/gui/sdlmain.cpp
@@ -7488,7 +7488,11 @@ static bool CheckEnableImmOnKey(SDL_KeyboardEvent key)
 #elif defined(WIN32) && !defined(HX_DOS) && defined(C_SDL2)
 static bool CheckEnableImmOnKey(SDL_KeyboardEvent key)
 {
-	if(key.keysym.scancode == 0x29 || (key.keysym.scancode >= 0x49 && key.keysym.scancode <= 0x52) || (key.keysym.scancode >= 0xe0 && key.keysym.scancode <= 0xe6) || (strPasteBuffer.length() && key.keysym.sym >= 0x20)) {
+	if(key.keysym.scancode == 0x29 ||
+#if defined(SDL_DOSBOX_X_IME)
+	(!SDL_IM_Composition() && (key.keysym.sym == 0x08 || key.keysym.sym == 0x09 || key.keysym.sym >= 0x20 && key.keysym.sym <= 0x7F || key.keysym.sym >= 0x111 && key.keysym.sym <= 0x119)) ||
+#endif
+	(key.keysym.scancode >= 0x49 && key.keysym.scancode <= 0x52) || (key.keysym.scancode >= 0xe0 && key.keysym.scancode <= 0xe6) || (strPasteBuffer.length() && key.keysym.sym >= 0x20)) {
 		// ESC, shift, control, alt, PgUp, PgDn, etc.
 		return true;
 	} else if((key.keysym.mod & 0x03) != 0 && key.keysym.scancode == 0x2c) {
diff --git a/src/shell/shell_misc.cpp b/src/shell/shell_misc.cpp
index c8f84bc5d..259e1cd99 100644
--- a/src/shell/shell_misc.cpp
+++ b/src/shell/shell_misc.cpp
@@ -50,9 +50,8 @@
 bool clearline=false, inshell=false;
 int autofixwarn=3;
 extern int lfn_filefind_handle;
-extern bool ctrlbrk, gbk, rtl;
-extern bool DOS_BreakFlag;
-extern bool DOS_BreakConioFlag;
+extern bool ctrlbrk, gbk, rtl, dbcs_sbcs;
+extern bool DOS_BreakFlag, DOS_BreakConioFlag;
 extern uint16_t cmd_line_seg;
 #if defined(USE_TTF)
 extern bool ttf_dosv;
@@ -558,7 +557,7 @@ void DOS_Shell::InputCommand(char * line) {
                 break;
 
             case 0x4B00:	/* LEFT */
-                if(IS_PC98_ARCH || (isDBCSCP() && IS_DOS_JAPANESE)) {
+                if(IS_PC98_ARCH || (isDBCSCP() && dbcs_sbcs && IS_DOS_JAPANESE)) {
                     if (str_index) {
                         uint16_t count = GetWideCount(line, str_index);
                         uint8_t ch = line[str_index - 1];
@@ -572,7 +571,7 @@ void DOS_Shell::InputCommand(char * line) {
                         }
                     }
                 } else {
-                    if (isDBCSCP()&&str_index>1&&(line[str_index-1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index-1]>=0x40))&&line[str_index-2]<0) {
+                    if (isDBCSCP()&&dbcs_sbcs&&str_index>1&&(line[str_index-1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index-1]>=0x40))&&line[str_index-2]<0) {
                         backone();
                         str_index --;
                         MoveCaretBackwards();
@@ -631,7 +630,7 @@ void DOS_Shell::InputCommand(char * line) {
 				}	
         		break;
             case 0x4D00:	/* RIGHT */
-                if(IS_PC98_ARCH || (isDBCSCP() && IS_DOS_JAPANESE)) {
+                if(IS_PC98_ARCH || (isDBCSCP() && dbcs_sbcs && IS_DOS_JAPANESE)) {
                     if (str_index < str_len) {
                         uint16_t count = 1;
                         if(str_index < str_len - 1) {
@@ -643,7 +642,7 @@ void DOS_Shell::InputCommand(char * line) {
                         }
                     }
                 } else {
-                    if (isDBCSCP()&&str_index<str_len-1&&line[str_index]<0&&(line[str_index+1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index+1]>=0x40))) {
+                    if (isDBCSCP()&&dbcs_sbcs&&str_index<str_len-1&&line[str_index]<0&&(line[str_index+1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index+1]>=0x40))) {
                         outc((uint8_t)line[str_index++]);
                     }
                     if (str_index < str_len) {
@@ -735,14 +734,14 @@ void DOS_Shell::InputCommand(char * line) {
 
                 break;
             case 0x5300:/* DELETE */
-                if(IS_PC98_ARCH || (isDBCSCP() && IS_DOS_JAPANESE)) {
+                if(IS_PC98_ARCH || (isDBCSCP() && dbcs_sbcs && IS_DOS_JAPANESE)) {
                     if(str_len) {
                         size += DeleteBackspace(true, line, str_index, str_len);
                     }
                 } else {
                     if(str_index>=str_len) break;
                     int k=1;
-                    if (isDBCSCP()&&str_index<str_len-1&&line[str_index]<0&&(line[str_index+1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index+1]>=0x40)))
+                    if (isDBCSCP()&&dbcs_sbcs&&str_index<str_len-1&&line[str_index]<0&&(line[str_index+1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index+1]>=0x40)))
                         k=2;
                     for (int i=0; i<k; i++) {
                         uint16_t a=str_len-str_index-1;
@@ -784,13 +783,13 @@ void DOS_Shell::InputCommand(char * line) {
                 }
                 break;
             case 0x08:				/* BackSpace */
-                if(IS_PC98_ARCH || (isDBCSCP() && IS_DOS_JAPANESE)) {
+                if(IS_PC98_ARCH || (isDBCSCP() && dbcs_sbcs && IS_DOS_JAPANESE)) {
                     if(str_index) {
                         size += DeleteBackspace(false, line, str_index, str_len);
                     }
                 } else {
                     int k=1;
-                    if (isDBCSCP()&&str_index>1&&(line[str_index-1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index-1]>=0x40))&&line[str_index-2]<0)
+                    if (isDBCSCP()&&dbcs_sbcs&&str_index>1&&(line[str_index-1]<0||((dos.loaded_codepage==932||(dos.loaded_codepage==936&&gbk)||dos.loaded_codepage==950||dos.loaded_codepage==951)&&line[str_index-1]>=0x40))&&line[str_index-2]<0)
                         k=2;
                     for (int i=0; i<k; i++)
                         if (str_index) {
@@ -950,7 +949,7 @@ void DOS_Shell::InputCommand(char * line) {
                 str_len = 0;
                 break;
             default:
-                if(IS_PC98_ARCH || (isDBCSCP() && IS_DOS_JAPANESE)) {
+                if(IS_PC98_ARCH || (isDBCSCP() && dbcs_sbcs && IS_DOS_JAPANESE)) {
                     bool kanji_flag = false;
                     uint16_t pos = str_index;
                     while(1) {
diff --git a/vs/sdl2/include/SDL_keyboard.h b/vs/sdl2/include/SDL_keyboard.h
index 874823171..93f08c248 100644
--- a/vs/sdl2/include/SDL_keyboard.h
+++ b/vs/sdl2/include/SDL_keyboard.h
@@ -149,6 +149,8 @@ extern DECLSPEC const char *SDLCALL SDL_GetKeyName(SDL_Keycode key);
  */
 extern DECLSPEC SDL_Keycode SDLCALL SDL_GetKeyFromName(const char *name);
 
+extern DECLSPEC SDL_bool SDLCALL SDL_IM_Composition(void);
+
 /**
  *  \brief Start accepting Unicode text input events.
  *         This function will show the on-screen keyboard if supported.
diff --git a/vs/sdl2/include/SDL_version.h b/vs/sdl2/include/SDL_version.h
index 31443e149..9354ca1eb 100644
--- a/vs/sdl2/include/SDL_version.h
+++ b/vs/sdl2/include/SDL_version.h
@@ -36,6 +36,9 @@
 extern "C" {
 #endif
 
+/* This is the DOSBox-X's modified SDL 2.x with IME support, not the general library */
+#define SDL_DOSBOX_X_IME 1
+
 /**
  *  \brief Information the version of SDL in use.
  *
diff --git a/vs/sdl2/src/video/windows/SDL_windowskeyboard.c b/vs/sdl2/src/video/windows/SDL_windowskeyboard.c
index e3e61a3f2..e6633ac3d 100644
--- a/vs/sdl2/src/video/windows/SDL_windowskeyboard.c
+++ b/vs/sdl2/src/video/windows/SDL_windowskeyboard.c
@@ -31,6 +31,8 @@
 #include <oleauto.h>
 
 #ifndef SDL_DISABLE_WINDOWS_IME
+static Uint32 end_ticks = 0;
+static SDL_bool ime_incompos;
 static void IME_Init(SDL_VideoData *videodata, HWND hwnd);
 static void IME_Enable(SDL_VideoData *videodata, HWND hwnd);
 static void IME_Disable(SDL_VideoData *videodata, HWND hwnd);
@@ -157,6 +159,15 @@ WIN_QuitKeyboard(_THIS)
 #endif
 }
 
+SDL_bool SDL_IM_Composition() {
+#ifndef SDL_DISABLE_WINDOWS_IME
+#define IME_END_CR_WAIT 50
+    return ime_incompos||end_ticks&&(GetTickCount()-end_ticks<IME_END_CR_WAIT) ? SDL_TRUE : SDL_FALSE;
+#else
+    return SDL_FALSE;
+#endif
+}
+
 void
 WIN_ResetDeadKeys()
 {
@@ -887,6 +898,7 @@ IME_HandleMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SDL_VideoD
         //*lParam = 0;
         break;
     case WM_IME_STARTCOMPOSITION:
+        ime_incompos = 1;
         //trap = SDL_TRUE;
         break;
     case WM_IME_COMPOSITION:
@@ -906,6 +918,8 @@ IME_HandleMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SDL_VideoD
         ImmReleaseContext(hwnd, himc);
         break;
     case WM_IME_ENDCOMPOSITION:
+        end_ticks = GetTickCount();
+        ime_incompos = 0;
         videodata->ime_composition[0] = 0;
         videodata->ime_readingstring[0] = 0;
         videodata->ime_cursor = 0;