diff --git a/lib/unicode.js b/lib/unicode.js
index 1c683e7..533321e 100644
--- a/lib/unicode.js
+++ b/lib/unicode.js
@@ -367,6 +367,14 @@ exports.charWidth = function(str, i) {
   }
   */
 
+  // http://www.unicode.org/reports/tr11/
+  // http://www.unicode.org/reports/tr11/#Ambiguous
+  if (process.env.NCURSES_CJK_WIDTH) {
+    if (exports.ambiguous[point]) {
+      return +process.env.NCURSES_CJK_WIDTH || 1;
+    }
+  }
+
   return 1;
 };
 
@@ -451,6 +459,68 @@ exports.isNonSpacing = function(str, i) {
   return exports.combining[point] === true;
 };
 
+exports.ambiguousTable = [
+  [ 0x00A1, 0x00A1 ], [ 0x00A4, 0x00A4 ], [ 0x00A7, 0x00A8 ],
+  [ 0x00AA, 0x00AA ], [ 0x00AE, 0x00AE ], [ 0x00B0, 0x00B4 ],
+  [ 0x00B6, 0x00BA ], [ 0x00BC, 0x00BF ], [ 0x00C6, 0x00C6 ],
+  [ 0x00D0, 0x00D0 ], [ 0x00D7, 0x00D8 ], [ 0x00DE, 0x00E1 ],
+  [ 0x00E6, 0x00E6 ], [ 0x00E8, 0x00EA ], [ 0x00EC, 0x00ED ],
+  [ 0x00F0, 0x00F0 ], [ 0x00F2, 0x00F3 ], [ 0x00F7, 0x00FA ],
+  [ 0x00FC, 0x00FC ], [ 0x00FE, 0x00FE ], [ 0x0101, 0x0101 ],
+  [ 0x0111, 0x0111 ], [ 0x0113, 0x0113 ], [ 0x011B, 0x011B ],
+  [ 0x0126, 0x0127 ], [ 0x012B, 0x012B ], [ 0x0131, 0x0133 ],
+  [ 0x0138, 0x0138 ], [ 0x013F, 0x0142 ], [ 0x0144, 0x0144 ],
+  [ 0x0148, 0x014B ], [ 0x014D, 0x014D ], [ 0x0152, 0x0153 ],
+  [ 0x0166, 0x0167 ], [ 0x016B, 0x016B ], [ 0x01CE, 0x01CE ],
+  [ 0x01D0, 0x01D0 ], [ 0x01D2, 0x01D2 ], [ 0x01D4, 0x01D4 ],
+  [ 0x01D6, 0x01D6 ], [ 0x01D8, 0x01D8 ], [ 0x01DA, 0x01DA ],
+  [ 0x01DC, 0x01DC ], [ 0x0251, 0x0251 ], [ 0x0261, 0x0261 ],
+  [ 0x02C4, 0x02C4 ], [ 0x02C7, 0x02C7 ], [ 0x02C9, 0x02CB ],
+  [ 0x02CD, 0x02CD ], [ 0x02D0, 0x02D0 ], [ 0x02D8, 0x02DB ],
+  [ 0x02DD, 0x02DD ], [ 0x02DF, 0x02DF ], [ 0x0391, 0x03A1 ],
+  [ 0x03A3, 0x03A9 ], [ 0x03B1, 0x03C1 ], [ 0x03C3, 0x03C9 ],
+  [ 0x0401, 0x0401 ], [ 0x0410, 0x044F ], [ 0x0451, 0x0451 ],
+  [ 0x2010, 0x2010 ], [ 0x2013, 0x2016 ], [ 0x2018, 0x2019 ],
+  [ 0x201C, 0x201D ], [ 0x2020, 0x2022 ], [ 0x2024, 0x2027 ],
+  [ 0x2030, 0x2030 ], [ 0x2032, 0x2033 ], [ 0x2035, 0x2035 ],
+  [ 0x203B, 0x203B ], [ 0x203E, 0x203E ], [ 0x2074, 0x2074 ],
+  [ 0x207F, 0x207F ], [ 0x2081, 0x2084 ], [ 0x20AC, 0x20AC ],
+  [ 0x2103, 0x2103 ], [ 0x2105, 0x2105 ], [ 0x2109, 0x2109 ],
+  [ 0x2113, 0x2113 ], [ 0x2116, 0x2116 ], [ 0x2121, 0x2122 ],
+  [ 0x2126, 0x2126 ], [ 0x212B, 0x212B ], [ 0x2153, 0x2154 ],
+  [ 0x215B, 0x215E ], [ 0x2160, 0x216B ], [ 0x2170, 0x2179 ],
+  [ 0x2190, 0x2199 ], [ 0x21B8, 0x21B9 ], [ 0x21D2, 0x21D2 ],
+  [ 0x21D4, 0x21D4 ], [ 0x21E7, 0x21E7 ], [ 0x2200, 0x2200 ],
+  [ 0x2202, 0x2203 ], [ 0x2207, 0x2208 ], [ 0x220B, 0x220B ],
+  [ 0x220F, 0x220F ], [ 0x2211, 0x2211 ], [ 0x2215, 0x2215 ],
+  [ 0x221A, 0x221A ], [ 0x221D, 0x2220 ], [ 0x2223, 0x2223 ],
+  [ 0x2225, 0x2225 ], [ 0x2227, 0x222C ], [ 0x222E, 0x222E ],
+  [ 0x2234, 0x2237 ], [ 0x223C, 0x223D ], [ 0x2248, 0x2248 ],
+  [ 0x224C, 0x224C ], [ 0x2252, 0x2252 ], [ 0x2260, 0x2261 ],
+  [ 0x2264, 0x2267 ], [ 0x226A, 0x226B ], [ 0x226E, 0x226F ],
+  [ 0x2282, 0x2283 ], [ 0x2286, 0x2287 ], [ 0x2295, 0x2295 ],
+  [ 0x2299, 0x2299 ], [ 0x22A5, 0x22A5 ], [ 0x22BF, 0x22BF ],
+  [ 0x2312, 0x2312 ], [ 0x2460, 0x24E9 ], [ 0x24EB, 0x254B ],
+  [ 0x2550, 0x2573 ], [ 0x2580, 0x258F ], [ 0x2592, 0x2595 ],
+  [ 0x25A0, 0x25A1 ], [ 0x25A3, 0x25A9 ], [ 0x25B2, 0x25B3 ],
+  [ 0x25B6, 0x25B7 ], [ 0x25BC, 0x25BD ], [ 0x25C0, 0x25C1 ],
+  [ 0x25C6, 0x25C8 ], [ 0x25CB, 0x25CB ], [ 0x25CE, 0x25D1 ],
+  [ 0x25E2, 0x25E5 ], [ 0x25EF, 0x25EF ], [ 0x2605, 0x2606 ],
+  [ 0x2609, 0x2609 ], [ 0x260E, 0x260F ], [ 0x2614, 0x2615 ],
+  [ 0x261C, 0x261C ], [ 0x261E, 0x261E ], [ 0x2640, 0x2640 ],
+  [ 0x2642, 0x2642 ], [ 0x2660, 0x2661 ], [ 0x2663, 0x2665 ],
+  [ 0x2667, 0x266A ], [ 0x266C, 0x266D ], [ 0x266F, 0x266F ],
+  [ 0x273D, 0x273D ], [ 0x2776, 0x277F ], [ 0xE000, 0xF8FF ],
+  [ 0xFFFD, 0xFFFD ], [ 0xF0000, 0xFFFFD ], [ 0x100000, 0x10FFFD ]
+];
+
+exports.ambiguous = exports.ambiguousTable.reduce(function(out, row) {
+  for (var i = row[0]; i <= row[1]; i++) {
+    out[i] = true;
+  }
+  return out;
+}, {});
+
 /**
  * Code Point Helpers
  */