diff --git a/lib/modules/Charset.pmod/module.pmod b/lib/modules/Charset.pmod/module.pmod
index 6cccbb3550e85080d6ceaaced1e224d0ac8aa095..d327c0bb67f7a4b8b15e7d8b7c164c9b09af9bd9 100644
--- a/lib/modules/Charset.pmod/module.pmod
+++ b/lib/modules/Charset.pmod/module.pmod
@@ -311,6 +311,7 @@ private class GSM03_38dec {
   {
     // Escape sequences for GSM 03.38.
     // cf http://en.wikipedia.org/wiki/Short_message_service
+    // https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=139
     string res =
       replace(trailer + decoder->drain(),
 	      "\eØ\e\u039b\e(\e)\e/\e<\e=\e>\eĄ\ee"/2,
diff --git a/src/modules/_Charset/misc.c b/src/modules/_Charset/misc.c
index 1e9961a81f4eb33a3cd7598512bc0ddc9ee3545b..2dccea2b1bb89189a72b47292ec5201f4a7aaebc 100644
--- a/src/modules/_Charset/misc.c
+++ b/src/modules/_Charset/misc.c
@@ -1903,24 +1903,49 @@ static const p_wchar1 map_mysql_latin1[] = {
   0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
   0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
   0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff, };
-/* From http://en.wikipedia.org/wiki/Short_message_service */
+/* GSM TS 03.38-7.2.0 6.2.1 Default alphabet
+ * From http://en.wikipedia.org/wiki/Short_message_service
+ * https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=139
+ */
 static const p_wchar1 map_gsm_03_38[] = {
   0x0040, 0x00a3, 0x0024, 0x00a5, 0x00e8, 0x00e9, 0x00f9, 0x00ec,
   0x00f2, 0x00c7, 0x000a, 0x00d8, 0x00f8, 0x000d, 0x00c5, 0x00e5,
   0x0394, 0x005f, 0x03a6, 0x0393, 0x039b, 0x03a9, 0x03a0, 0x03a8,
   0x03a3, 0x0398, 0x039e, 0x001b, 0x00c6, 0x00e6, 0x00df, 0x00c9,
-  0x0020, 0x0021, 0x0022, 0x0023, 0x00a4, 0x0025, 0x0026, 0x0027, 
-  0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f, 
-  0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 
-  0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f, 
-  0x00a1, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 
-  0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, 
-  0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 
-  0x0058, 0x0059, 0x005a, 0x00c4, 0x00d6, 0x00d1, 0x00dc, 0x00a7, 
-  0x00bf, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 
-  0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f, 
-  0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 
-  0x0078, 0x0079, 0x007a, 0x00e5, 0x00e4, 0x00f1, 0x00fc, 0x00e0, 
+  0x0020, 0x0021, 0x0022, 0x0023, 0x00a4, 0x0025, 0x0026, 0x0027,
+  0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+  0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+  0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+  0x00a1, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+  0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+  0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+  0x0058, 0x0059, 0x005a, 0x00c4, 0x00d6, 0x00d1, 0x00dc, 0x00a7,
+  0x00bf, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
+  0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+  0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
+  0x0078, 0x0079, 0x007a, 0x00e4, 0x00f6, 0x00f1, 0x00fc, 0x00e0,
+};
+/* GSM TS 03.38-7.2.0 6.2.1.1 GSM 7bit default alphabet extension table
+ * From http://en.wikipedia.org/wiki/Short_message_service
+ * https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=139
+ */
+static const p_wchar1 map_gsm_03_38_ext[] = {
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0x000c, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0x005e, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0x001b, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0x007b, 0x007d, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0x005c,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0x005b, 0x007e, 0x005d, 0xfffd,
+  0x007c, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0x20ac, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
+  0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd, 0xfffd,
 };
 
 
@@ -2034,6 +2059,8 @@ static const struct {
   { "ebcdicus", map_EBCDIC_US, 32, 255 },                             /* :: ebcdic-us */
   { "gsm", map_gsm_03_38, 0, 127 },                                   /* :: gsm 03.38 */
   { "gsm0338", map_gsm_03_38, 0, 127 },                               /* :: gsm 03.38 */
+  { "gsmext", map_gsm_03_38_ext, 0, 127 },                            /* :: gsm 03.38-ext */
+  { "gsm0338ext", map_gsm_03_38_ext, 0, 127 },                        /* :: gsm 03.38-ext */
   { "halfwidthkatakana", map_JIS_X0201, 92, 255 },
   { "hproman8", map_hp_roman8, 161, 255 },                            /* :: hp-roman8 */
   { "ibmebcdicatde", map_EBCDIC_AT_DE, 32, 255 },