diff --git a/lib/internal/readline/utils.js b/lib/internal/readline/utils.js
index 7c24a8e195a301..3257ee3a1e4a1f 100644
--- a/lib/internal/readline/utils.js
+++ b/lib/internal/readline/utils.js
@@ -63,6 +63,9 @@ if (internalBinding('config').hasIntl) {
   const icu = internalBinding('icu');
   // icu.getStringWidth(string, ambiguousAsFullWidth, expandEmojiSequence)
   // Defaults: ambiguousAsFullWidth = false; expandEmojiSequence = true;
+  // TODO(BridgeAR): Expose the options to the user. That is probably the
+  // best thing possible at the moment, since it's difficult to know what
+  // the receiving end supports.
   getStringWidth = function getStringWidth(str) {
     let width = 0;
     str = stripVTControlCharacters(str);
diff --git a/src/node_i18n.cc b/src/node_i18n.cc
index 7cb7ab35d5060c..46c6ef39f861ec 100644
--- a/src/node_i18n.cc
+++ b/src/node_i18n.cc
@@ -767,18 +767,10 @@ static int GetColumnWidth(UChar32 codepoint,
 // Returns the column width for the given String.
 static void GetStringWidth(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
-  if (args.Length() < 1)
-    return;
+  CHECK(args[0]->IsString());
 
   bool ambiguous_as_full_width = args[1]->IsTrue();
-  bool expand_emoji_sequence = args[2]->IsTrue();
-
-  if (args[0]->IsNumber()) {
-    uint32_t val;
-    if (!args[0]->Uint32Value(env->context()).To(&val)) return;
-    args.GetReturnValue().Set(GetColumnWidth(val, ambiguous_as_full_width));
-    return;
-  }
+  bool expand_emoji_sequence = !args[2]->IsBoolean() || args[2]->IsTrue();
 
   TwoByteValue value(env->isolate(), args[0]);
   // reinterpret_cast is required by windows to compile
@@ -803,6 +795,7 @@ static void GetStringWidth(const FunctionCallbackInfo<Value>& args) {
     // in advance if a particular sequence is going to be supported.
     // The expand_emoji_sequence option allows the caller to skip this
     // check and count each code within an emoji sequence separately.
+    // https://www.unicode.org/reports/tr51/tr51-16.html#Emoji_ZWJ_Sequences
     if (!expand_emoji_sequence &&
         n > 0 && p == 0x200d &&  // 0x200d == ZWJ (zero width joiner)
         (u_hasBinaryProperty(c, UCHAR_EMOJI_PRESENTATION) ||
diff --git a/test/parallel/test-icu-stringwidth.js b/test/parallel/test-icu-stringwidth.js
index 48384f916d9126..a427601803afd3 100644
--- a/test/parallel/test-icu-stringwidth.js
+++ b/test/parallel/test-icu-stringwidth.js
@@ -12,82 +12,78 @@ const readline = require('internal/readline/utils');
 
 // Ll (Lowercase Letter): LATIN SMALL LETTER A
 assert.strictEqual(readline.getStringWidth('a'), 1);
-assert.strictEqual(readline.getStringWidth(0x0061), 1);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x0061)), 1);
 // Lo (Other Letter)
 assert.strictEqual(readline.getStringWidth('丁'), 2);
-assert.strictEqual(readline.getStringWidth(0x4E01), 2);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x4E01)), 2);
 // Surrogate pairs
-assert.strictEqual(readline.getStringWidth('\ud83d\udc78\ud83c\udfff'), 2);
+assert.strictEqual(readline.getStringWidth('\ud83d\udc78\ud83c\udfff'), 4);
 assert.strictEqual(readline.getStringWidth('👅'), 2);
 // Cs (Surrogate): High Surrogate
 assert.strictEqual(readline.getStringWidth('\ud83d'), 1);
 // Cs (Surrogate): Low Surrogate
 assert.strictEqual(readline.getStringWidth('\udc78'), 1);
 // Cc (Control): NULL
-assert.strictEqual(readline.getStringWidth(0), 0);
+assert.strictEqual(readline.getStringWidth('\u0000'), 0);
 // Cc (Control): BELL
-assert.strictEqual(readline.getStringWidth(0x0007), 0);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x0007)), 0);
 // Cc (Control): LINE FEED
 assert.strictEqual(readline.getStringWidth('\n'), 0);
 // Cf (Format): SOFT HYPHEN
-assert.strictEqual(readline.getStringWidth(0x00AD), 1);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x00AD)), 1);
 // Cf (Format): LEFT-TO-RIGHT MARK
 // Cf (Format): RIGHT-TO-LEFT MARK
 assert.strictEqual(readline.getStringWidth('\u200Ef\u200F'), 1);
 // Cn (Unassigned): Not a character
-assert.strictEqual(readline.getStringWidth(0x10FFEF), 1);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x10FFEF)), 1);
 // Cn (Unassigned): Not a character (but in a CJK range)
-assert.strictEqual(readline.getStringWidth(0x3FFEF), 2);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x3FFEF)), 1);
 // Mn (Nonspacing Mark): COMBINING ACUTE ACCENT
-assert.strictEqual(readline.getStringWidth(0x0301), 0);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x0301)), 0);
 // Mc (Spacing Mark): BALINESE ADEG ADEG
 // Chosen as its Canonical_Combining_Class is not 0, but is not a 0-width
 // character.
-assert.strictEqual(readline.getStringWidth(0x1B44), 1);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x1B44)), 1);
 // Me (Enclosing Mark): COMBINING ENCLOSING CIRCLE
-assert.strictEqual(readline.getStringWidth(0x20DD), 0);
+assert.strictEqual(readline.getStringWidth(String.fromCharCode(0x20DD)), 0);
 
-// The following is an emoji sequence. In some implementations, it is
-// represented as a single glyph, in other implementations as a sequence
-// of individual glyphs. By default, the algorithm will assume the single
-// glyph interpretation and return a value of 2. By passing the
-// expandEmojiSequence: true option, each component will be counted
-// individually.
-assert.strictEqual(readline.getStringWidth('👩‍👩‍👧‍👧'), 2);
-assert.strictEqual(
-  readline.getStringWidth('👩‍👩‍👧‍👧', { expandEmojiSequence: true }), 8);
+// The following is an emoji sequence with ZWJ (zero-width-joiner). In some
+// implementations, it is represented as a single glyph, in other
+// implementations as a sequence of individual glyphs. By default, each
+// component will be counted individually, since not a lot of systems support
+// these fully.
+// See https://www.unicode.org/reports/tr51/tr51-16.html#Emoji_ZWJ_Sequences
+assert.strictEqual(readline.getStringWidth('👩‍👩‍👧‍👧'), 8);
+// TODO(BridgeAR): This should have a width of two and six. The heart contains
+// the \uFE0F variation selector that indicates that it should be displayed as
+// emoji instead of as text. Emojis are all full width characters when not being
+// rendered as text.
+// https://en.wikipedia.org/wiki/Variation_Selectors_(Unicode_block)
+assert.strictEqual(readline.getStringWidth('❤️'), 1);
+assert.strictEqual(readline.getStringWidth('👩‍❤️‍👩'), 5);
+// The length of one is correct. It is an emoji treated as text.
+assert.strictEqual(readline.getStringWidth('❤'), 1);
 
 // By default, unicode characters whose width is considered ambiguous will
 // be considered half-width. For these characters, getStringWidth will return
 // 1. In some contexts, however, it is more appropriate to consider them full
-// width. By default, the algorithm will assume half width. By passing
-// the ambiguousAsFullWidth: true option, ambiguous characters will be counted
-// as 2 columns.
+// width. By default, the algorithm will assume half width.
 assert.strictEqual(readline.getStringWidth('\u01d4'), 1);
-assert.strictEqual(
-  readline.getStringWidth('\u01d4', { ambiguousAsFullWidth: true }), 2);
 
 // Control chars and combining chars are zero
 assert.strictEqual(readline.getStringWidth('\u200E\n\u220A\u20D2'), 1);
 
 // Test that the fast path for ASCII characters yields results consistent
 // with the 'slow' path.
-for (const ambiguousAsFullWidth of [ false, true ]) {
-  for (let i = 0; i < 256; i++) {
-    const char = String.fromCharCode(i);
-    assert.strictEqual(
-      readline.getStringWidth(i, { ambiguousAsFullWidth }),
-      readline.getStringWidth(char, { ambiguousAsFullWidth }));
-    assert.strictEqual(
-      readline.getStringWidth(char + '🎉', { ambiguousAsFullWidth }),
-      readline.getStringWidth(char, { ambiguousAsFullWidth }) + 2);
+for (let i = 0; i < 256; i++) {
+  const char = String.fromCharCode(i);
+  assert.strictEqual(
+    readline.getStringWidth(char + '🎉'),
+    readline.getStringWidth(char) + 2);
 
-    if (i < 32 || (i >= 127 && i < 160)) {  // Control character
-      assert.strictEqual(
-        readline.getStringWidth(i, { ambiguousAsFullWidth }), 0);
-    } else if (i < 127) {  // Regular ASCII character
-      assert.strictEqual(
-        readline.getStringWidth(i, { ambiguousAsFullWidth }), 1);
-    }
+  if (i < 32 || (i >= 127 && i < 160)) {  // Control character
+    assert.strictEqual(readline.getStringWidth(char), 0);
+  } else {  // Regular ASCII character
+    assert.strictEqual(readline.getStringWidth(char), 1);
   }
 }