diff --git a/src/runtime/pprof/proto_test.go b/src/runtime/pprof/proto_test.go
index 84a051a..1462c20 100644
--- a/src/runtime/pprof/proto_test.go
+++ b/src/runtime/pprof/proto_test.go
@@ -95,11 +95,11 @@ func testPCs(t *testing.T) (addr1, addr2 uint64, map1, map2 *profile.Mapping) {
 			// region of memory.
 			t.Skipf("need 2 or more mappings, got %v", len(mprof.Mapping))
 		}
-		addr1 = mprof.Mapping[0].Start
-		map1 = mprof.Mapping[0]
+		addr1 = mprof.Mapping[1].Start
+		map1 = mprof.Mapping[1]
 		map1.BuildID, _ = elfBuildID(map1.File)
-		addr2 = mprof.Mapping[1].Start
-		map2 = mprof.Mapping[1]
+		addr2 = mprof.Mapping[2].Start
+		map2 = mprof.Mapping[2]
 		map2.BuildID, _ = elfBuildID(map2.File)
 	case "js":
 		addr1 = uint64(abi.FuncPCABIInternal(f1))