diff --git a/benchmark_test.go b/benchmark_test.go
index bffd78a..3dc15ea 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -37,8 +37,8 @@ func BenchmarkTableAmbiguous(b *testing.B) {
 func BenchmarkTableEmoji(b *testing.B) {
 	benchSink = benchTable(b, emoji)
 }
-func BenchmarkTableNotassigned(b *testing.B) {
-	benchSink = benchTable(b, notassigned)
+func BenchmarkTableNarrow(b *testing.B) {
+	benchSink = benchTable(b, narrow)
 }
 func BenchmarkTableNeutral(b *testing.B) {
 	benchSink = benchTable(b, neutral)
diff --git a/runewidth.go b/runewidth.go
index f3871a6..e667419 100644
--- a/runewidth.go
+++ b/runewidth.go
@@ -97,8 +97,10 @@ func NewCondition() *Condition {
 // See http://www.unicode.org/reports/tr11/
 func (c *Condition) RuneWidth(r rune) int {
 	switch {
-	case r < 0 || r > 0x10FFFF || inTables(r, nonprint, combining, notassigned):
+	case r < 0 || r > 0x10FFFF || inTables(r, nonprint, combining):
 		return 0
+	case inTables(r, narrow):
+		return 1
 	case (c.EastAsianWidth && IsAmbiguousWidth(r)) || inTables(r, doublewidth):
 		return 2
 	default:
diff --git a/runewidth_table.go b/runewidth_table.go
index b27d77d..e5d890c 100644
--- a/runewidth_table.go
+++ b/runewidth_table.go
@@ -124,8 +124,10 @@ var ambiguous = table{
 	{0x1F18F, 0x1F190}, {0x1F19B, 0x1F1AC}, {0xE0100, 0xE01EF},
 	{0xF0000, 0xFFFFD}, {0x100000, 0x10FFFD},
 }
-var notassigned = table{
-	{0x27E6, 0x27ED}, {0x2985, 0x2986},
+var narrow = table{
+	{0x0020, 0x007E}, {0x00A2, 0x00A3}, {0x00A5, 0x00A6},
+	{0x00AC, 0x00AC}, {0x00AF, 0x00AF}, {0x27E6, 0x27ED},
+	{0x2985, 0x2986},
 }
 
 var neutral = table{
diff --git a/runewidth_test.go b/runewidth_test.go
index 89c943f..b93e652 100644
--- a/runewidth_test.go
+++ b/runewidth_test.go
@@ -44,7 +44,7 @@ var tables = []tableInfo{
 	{doublewidth, "doublewidth", 182440, "3d16eda8650dc2c92d6318d32f0b4a74fda5a278db2d4544b1dd65863394823c"},
 	{ambiguous, "ambiguous", 138739, "d05e339a10f296de6547ff3d6c5aee32f627f6555477afebd4a3b7e3cf74c9e3"},
 	{emoji, "emoji", 3535, "9ec17351601d49c535658de8d129c1d0ccda2e620669fc39a2faaee7dedcef6d"},
-	{notassigned, "notassigned", 10, "68441e98eca1450efbe857ac051fcc872eed347054dfd0bc662d1c4ee021d69f"},
+	{narrow, "narrow", 111, "fa897699c5e3cd9141c638d539331b0bdd508b874e22996c5e929767d455fc5a"},
 	{neutral, "neutral", 27333, "5455f5e75c307f70b4e9b2384dc5a8bcd91a4c5e2b24b2b185dfad4d860ee5c2"},
 }
 
@@ -164,6 +164,8 @@ var runewidthtests = []struct {
 	{'\u0300', 0, 0},
 	{'\u2028', 0, 0},
 	{'\u2029', 0, 0},
+	{'a', 1, 1}, // ASCII classified as "na" (narrow)
+	{'⟦', 1, 1}, // non-ASCII classified as "na" (narrow)
 }
 
 func TestRuneWidth(t *testing.T) {
diff --git a/script/generate.go b/script/generate.go
index 2b64b24..cd7f923 100644
--- a/script/generate.go
+++ b/script/generate.go
@@ -92,12 +92,10 @@ func eastasian(out io.Writer, in io.Reader) error {
 				hi: r2,
 			})
 		case "Na":
-			if r1 > 0xFF {
-				na = append(na, rrange{
-					lo: r1,
-					hi: r2,
-				})
-			}
+			na = append(na, rrange{
+				lo: r1,
+				hi: r2,
+			})
 		case "N":
 			nu = append(nu, rrange{
 				lo: r1,
@@ -119,7 +117,7 @@ func eastasian(out io.Writer, in io.Reader) error {
 	fmt.Fprint(out)
 
 	shapeup(&na)
-	generate(out, "notassigned", na)
+	generate(out, "narrow", na)
 	fmt.Fprintln(out)
 
 	shapeup(&nu)