diff --git a/src/runtime/symtab_test.go b/src/runtime/symtab_test.go
index bd9fe18..d94de04 100644
--- a/src/runtime/symtab_test.go
+++ b/src/runtime/symtab_test.go
@@ -45,3 +45,55 @@ func testCallerBar(t *testing.T) {
                }
        }
 }
+
+func lineNumber() int {
+       _, _, line, _ := runtime.Caller(1)
+       return line // return 0 for error
+}
+
+// Do not add/remove lines in this block without updating the line numbers.
+var firstLine = lineNumber() // 0
+var (                        // 1
+       lineVar1             = lineNumber()               // 2
+       lineVar2a, lineVar2b = lineNumber(), lineNumber() // 3
+)                        // 4
+var compLit = []struct { // 5
+       lineA, lineB int // 6
+}{ // 7
+       { // 8
+               lineNumber(), lineNumber(), // 9
+       }, // 10
+       { // 11
+               lineNumber(), // 12
+               lineNumber(), // 13
+       }, // 14
+       { // 15
+               lineB: lineNumber(), // 16
+               lineA: lineNumber(), // 17
+       }, // 18
+} // 19
+// Modifications below this line are okay.
+
+func TestLineNumber(t *testing.T) {
+       for _, test := range []struct {
+               name string
+               val  int
+               want int
+       }{
+               {"firstLine", firstLine, 0},
+               {"lineVar1", lineVar1, 2},
+               {"lineVar2a", lineVar2a, 3},
+               {"lineVar2b", lineVar2b, 3},
+               {"compLit[0].lineA", compLit[0].lineA, 9},
+               {"compLit[0].lineB", compLit[0].lineB, 9},
+               {"compLit[1].lineA", compLit[1].lineA, 12},
+               {"compLit[1].lineB", compLit[1].lineB, 13},
+               {"compLit[2].lineA", compLit[2].lineA, 17},
+               {"compLit[2].lineB", compLit[2].lineB, 16},
+       } {
+               if got := test.val - firstLine; got != test.want {
+                       t.Errorf("%s on firstLine+%d want firstLine+%d (firstLine=%d, val=%d)",
+                               test.name, got, test.want, firstLine, test.val)
+               }
+       }
+}

$ go test -short runtime
--- FAIL: TestLineNumber (0.00s)
    symtab_test.go:96: compLit[0].lineA on firstLine+19 want firstLine+9 (firstLine=55, val=74)
    symtab_test.go:96: compLit[0].lineB on firstLine+19 want firstLine+9 (firstLine=55, val=74)
    symtab_test.go:96: compLit[1].lineA on firstLine+19 want firstLine+12 (firstLine=55, val=74)
    symtab_test.go:96: compLit[1].lineB on firstLine+19 want firstLine+13 (firstLine=55, val=74)
    symtab_test.go:96: compLit[2].lineA on firstLine+19 want firstLine+17 (firstLine=55, val=74)
    symtab_test.go:96: compLit[2].lineB on firstLine+19 want firstLine+16 (firstLine=55, val=74)
FAIL
FAIL    runtime 11.072s