diff --git a/src/runtime/string.go b/src/runtime/string.go
index e1142034..70507861 100644
--- a/src/runtime/string.go
+++ b/src/runtime/string.go
@@ -14,8 +14,7 @@ type _string struct {
 
 // The iterator state for a range over a string.
 type stringIterator struct {
-	byteindex  uintptr
-	rangeindex uintptr
+	byteindex uintptr
 }
 
 // Return true iff the strings match.
@@ -105,10 +104,10 @@ func stringNext(s string, it *stringIterator) (bool, int, rune) {
 	if len(s) <= int(it.byteindex) {
 		return false, 0, 0
 	}
+	i := int(it.byteindex)
 	r, length := decodeUTF8(s, it.byteindex)
 	it.byteindex += length
-	it.rangeindex += 1
-	return true, int(it.rangeindex), r
+	return true, i, r
 }
 
 // Convert a Unicode code point into an array of bytes and its length.
diff --git a/testdata/rangestring.go b/testdata/rangestring.go
new file mode 100644
index 00000000..32401c2c
--- /dev/null
+++ b/testdata/rangestring.go
@@ -0,0 +1,11 @@
+package main
+
+func testRangeString() {
+	for i, c := range "abcü¢€𐍈°x" {
+		println(i, c)
+	}
+}
+
+func main() {
+	testRangeString()
+}
diff --git a/testdata/rangestring.txt b/testdata/rangestring.txt
new file mode 100644
index 00000000..e3318b41
--- /dev/null
+++ b/testdata/rangestring.txt
@@ -0,0 +1,9 @@
+0 97
+1 98
+2 99
+3 252
+5 162
+7 8364
+10 66376
+14 176
+16 120