diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -1027,6 +1027,8 @@
 +-----------------+--------------------------------+--------------------------------+
 | cp1026          | ibm1026                        | Turkish                        |
 +-----------------+--------------------------------+--------------------------------+
+| cp1125          | 1125, ibm1125, cp866u, ruscii  | Ukrainian                      |
++-----------------+--------------------------------+--------------------------------+
 | cp1140          | ibm1140                        | Western Europe                 |
 +-----------------+--------------------------------+--------------------------------+
 | cp1250          | windows-1250                   | Central and Eastern Europe     |
diff --git a/Lib/encodings/aliases.py b/Lib/encodings/aliases.py
--- a/Lib/encodings/aliases.py
+++ b/Lib/encodings/aliases.py
@@ -63,6 +63,13 @@
     'csibm1026'          : 'cp1026',
     'ibm1026'            : 'cp1026',
 
+    # cp1125 codec
+    '1125'                : 'cp1125',
+    'ibm1125'             : 'cp1125',
+    'cp866u'              : 'cp1125',
+    'cp866nav'            : 'cp1125',
+    'ruscii'              : 'cp1125',
+
     # cp1140 codec
     '1140'               : 'cp1140',
     'ibm1140'            : 'cp1140',
diff --git a/Lib/encodings/cp866.py b/Lib/encodings/cp1125.py
copy from Lib/encodings/cp866.py
copy to Lib/encodings/cp1125.py
--- a/Lib/encodings/cp866.py
+++ b/Lib/encodings/cp1125.py
@@ -1,4 +1,4 @@
-""" Python Character Mapping Codec generated from 'VENDORS/MICSFT/PC/CP866.TXT' with gencodec.py.
+""" Python Character Mapping Codec for CP1125
 
 """#"
 
@@ -32,7 +32,7 @@
 
 def getregentry():
     return codecs.CodecInfo(
-        name='cp866',
+        name='cp1125',
         encode=Codec().encode,
         decode=Codec().decode,
         incrementalencoder=IncrementalEncoder,
@@ -159,14 +159,14 @@
     0x00ef: 0x044f,     #  CYRILLIC SMALL LETTER YA
     0x00f0: 0x0401,     #  CYRILLIC CAPITAL LETTER IO
     0x00f1: 0x0451,     #  CYRILLIC SMALL LETTER IO
-    0x00f2: 0x0404,     #  CYRILLIC CAPITAL LETTER UKRAINIAN IE
-    0x00f3: 0x0454,     #  CYRILLIC SMALL LETTER UKRAINIAN IE
-    0x00f4: 0x0407,     #  CYRILLIC CAPITAL LETTER YI
-    0x00f5: 0x0457,     #  CYRILLIC SMALL LETTER YI
-    0x00f6: 0x040e,     #  CYRILLIC CAPITAL LETTER SHORT U
-    0x00f7: 0x045e,     #  CYRILLIC SMALL LETTER SHORT U
-    0x00f8: 0x00b0,     #  DEGREE SIGN
-    0x00f9: 0x2219,     #  BULLET OPERATOR
+    0x00f2: 0x0490,     #  CYRILLIC CAPITAL LETTER GHE WITH UPTURN
+    0x00f3: 0x0491,     #  CYRILLIC SMALL LETTER GHE WITH UPTURN
+    0x00f4: 0x0404,     #  CYRILLIC CAPITAL LETTER UKRAINIAN IE
+    0x00f5: 0x0454,     #  CYRILLIC SMALL LETTER UKRAINIAN IE
+    0x00f6: 0x0406,     #  CYRILLIC CAPITAL LETTER BYELORUSSIAN-UKRAINIAN I
+    0x00f7: 0x0456,     #  CYRILLIC SMALL LETTER BYELORUSSIAN-UKRAINIAN I
+    0x00f8: 0x0407,     #  CYRILLIC CAPITAL LETTER YI
+    0x00f9: 0x0457,     #  CYRILLIC SMALL LETTER YI
     0x00fa: 0x00b7,     #  MIDDLE DOT
     0x00fb: 0x221a,     #  SQUARE ROOT
     0x00fc: 0x2116,     #  NUMERO SIGN
@@ -420,14 +420,14 @@
     '\u044f'   #  0x00ef -> CYRILLIC SMALL LETTER YA
     '\u0401'   #  0x00f0 -> CYRILLIC CAPITAL LETTER IO
     '\u0451'   #  0x00f1 -> CYRILLIC SMALL LETTER IO
-    '\u0404'   #  0x00f2 -> CYRILLIC CAPITAL LETTER UKRAINIAN IE
-    '\u0454'   #  0x00f3 -> CYRILLIC SMALL LETTER UKRAINIAN IE
-    '\u0407'   #  0x00f4 -> CYRILLIC CAPITAL LETTER YI
-    '\u0457'   #  0x00f5 -> CYRILLIC SMALL LETTER YI
-    '\u040e'   #  0x00f6 -> CYRILLIC CAPITAL LETTER SHORT U
-    '\u045e'   #  0x00f7 -> CYRILLIC SMALL LETTER SHORT U
-    '\xb0'     #  0x00f8 -> DEGREE SIGN
-    '\u2219'   #  0x00f9 -> BULLET OPERATOR
+    '\u0490'   #  0x00f2 -> CYRILLIC CAPITAL LETTER GHE WITH UPTURN
+    '\u0491'   #  0x00f3 -> CYRILLIC SMALL LETTER GHE WITH UPTURN
+    '\u0404'   #  0x00f4 -> CYRILLIC CAPITAL LETTER UKRAINIAN IE
+    '\u0454'   #  0x00f5 -> CYRILLIC SMALL LETTER UKRAINIAN IE
+    '\u0406'   #  0x00f6 -> CYRILLIC CAPITAL LETTER BYELORUSSIAN-UKRAINIAN I
+    '\u0456'   #  0x00f7 -> CYRILLIC SMALL LETTER BYELORUSSIAN-UKRAINIAN I
+    '\u0407'   #  0x00f8 -> CYRILLIC CAPITAL LETTER YI
+    '\u0457'   #  0x00f9 -> CYRILLIC SMALL LETTER YI
     '\xb7'     #  0x00fa -> MIDDLE DOT
     '\u221a'   #  0x00fb -> SQUARE ROOT
     '\u2116'   #  0x00fc -> NUMERO SIGN
@@ -569,12 +569,11 @@
     0x007f: 0x007f,     #  DELETE
     0x00a0: 0x00ff,     #  NO-BREAK SPACE
     0x00a4: 0x00fd,     #  CURRENCY SIGN
-    0x00b0: 0x00f8,     #  DEGREE SIGN
     0x00b7: 0x00fa,     #  MIDDLE DOT
     0x0401: 0x00f0,     #  CYRILLIC CAPITAL LETTER IO
-    0x0404: 0x00f2,     #  CYRILLIC CAPITAL LETTER UKRAINIAN IE
-    0x0407: 0x00f4,     #  CYRILLIC CAPITAL LETTER YI
-    0x040e: 0x00f6,     #  CYRILLIC CAPITAL LETTER SHORT U
+    0x0404: 0x00f4,     #  CYRILLIC CAPITAL LETTER UKRAINIAN IE
+    0x0406: 0x00f6,     #  CYRILLIC CAPITAL LETTER BYELORUSSIAN-UKRAINIAN I
+    0x0407: 0x00f8,     #  CYRILLIC CAPITAL LETTER YI
     0x0410: 0x0080,     #  CYRILLIC CAPITAL LETTER A
     0x0411: 0x0081,     #  CYRILLIC CAPITAL LETTER BE
     0x0412: 0x0082,     #  CYRILLIC CAPITAL LETTER VE
@@ -640,11 +639,12 @@
     0x044e: 0x00ee,     #  CYRILLIC SMALL LETTER YU
     0x044f: 0x00ef,     #  CYRILLIC SMALL LETTER YA
     0x0451: 0x00f1,     #  CYRILLIC SMALL LETTER IO
-    0x0454: 0x00f3,     #  CYRILLIC SMALL LETTER UKRAINIAN IE
-    0x0457: 0x00f5,     #  CYRILLIC SMALL LETTER YI
-    0x045e: 0x00f7,     #  CYRILLIC SMALL LETTER SHORT U
+    0x0454: 0x00f5,     #  CYRILLIC SMALL LETTER UKRAINIAN IE
+    0x0456: 0x00f7,     #  CYRILLIC SMALL LETTER BYELORUSSIAN-UKRAINIAN I
+    0x0457: 0x00f9,     #  CYRILLIC SMALL LETTER YI
+    0x0490: 0x00f2,     #  CYRILLIC CAPITAL LETTER GHE WITH UPTURN
+    0x0491: 0x00f3,     #  CYRILLIC SMALL LETTER GHE WITH UPTURN
     0x2116: 0x00fc,     #  NUMERO SIGN
-    0x2219: 0x00f9,     #  BULLET OPERATOR
     0x221a: 0x00fb,     #  SQUARE ROOT
     0x2500: 0x00c4,     #  BOX DRAWINGS LIGHT HORIZONTAL
     0x2502: 0x00b3,     #  BOX DRAWINGS LIGHT VERTICAL
diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
--- a/Lib/test/test_codecs.py
+++ b/Lib/test/test_codecs.py
@@ -1601,6 +1601,7 @@
     "cp037",
     "cp1006",
     "cp1026",
+    "cp1125",
     "cp1140",
     "cp1250",
     "cp1251",
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -1834,7 +1834,7 @@
             'cp037', 'cp1026', 'cp273',
             'cp437', 'cp500', 'cp720', 'cp737', 'cp775', 'cp850',
             'cp852', 'cp855', 'cp858', 'cp860', 'cp861', 'cp862',
-            'cp863', 'cp865', 'cp866',
+            'cp863', 'cp865', 'cp866', 'cp1125',
             'iso8859_10', 'iso8859_13', 'iso8859_14', 'iso8859_15',
             'iso8859_2', 'iso8859_3', 'iso8859_4', 'iso8859_5', 'iso8859_6',
             'iso8859_7', 'iso8859_9', 'koi8_r', 'latin_1',
@@ -1862,7 +1862,7 @@
             'cp037', 'cp1026', 'cp273',
             'cp437', 'cp500', 'cp720', 'cp737', 'cp775', 'cp850',
             'cp852', 'cp855', 'cp858', 'cp860', 'cp861', 'cp862',
-            'cp863', 'cp865', 'cp866',
+            'cp863', 'cp865', 'cp866', 'cp1125',
             'iso8859_10', 'iso8859_13', 'iso8859_14', 'iso8859_15',
             'iso8859_2', 'iso8859_4', 'iso8859_5',
             'iso8859_9', 'koi8_r', 'latin_1',
diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -692,9 +692,9 @@
             'iso8859-13', 'iso8859-14', 'iso8859-15', 'iso8859-16',
             'cp437', 'cp720', 'cp737', 'cp775', 'cp850', 'cp852',
             'cp855', 'cp856', 'cp857', 'cp858', 'cp860', 'cp861', 'cp862',
-            'cp863', 'cp865', 'cp866', 'cp869', 'cp874', 'cp1006', 'cp1250',
-            'cp1251', 'cp1252', 'cp1253', 'cp1254', 'cp1255', 'cp1256',
-            'cp1257', 'cp1258',
+            'cp863', 'cp865', 'cp866', 'cp869', 'cp874', 'cp1006', 'cp1125',
+            'cp1250', 'cp1251', 'cp1252', 'cp1253', 'cp1254', 'cp1255',
+            'cp1256', 'cp1257', 'cp1258',
             'mac-cyrillic', 'mac-greek', 'mac-iceland', 'mac-latin2',
             'mac-roman', 'mac-turkish',
             'iso2022-jp', 'iso2022-jp-1', 'iso2022-jp-2', 'iso2022-jp-2004',