diff --git a/src/google/protobuf/compiler/parser.cc b/src/google/protobuf/compiler/parser.cc
index 152f8f50132c..0576b64a4c97 100644
--- a/src/google/protobuf/compiler/parser.cc
+++ b/src/google/protobuf/compiler/parser.cc
@@ -902,10 +902,8 @@ bool Parser::ParseMessageField(FieldDescriptorProto* field,
                                const LocationRecorder& field_location,
                                const FileDescriptorProto* containing_file) {
   {
-    LocationRecorder location(field_location,
-                              FieldDescriptorProto::kLabelFieldNumber);
     FieldDescriptorProto::Label label;
-    if (ParseLabel(&label, containing_file)) {
+    if (ParseLabel(&label, field_location, containing_file)) {
       field->set_label(label);
       if (label == FieldDescriptorProto::LABEL_OPTIONAL &&
           syntax_identifier_ == "proto3") {
@@ -2206,18 +2204,22 @@ bool Parser::ParseMethodOptions(const LocationRecorder& parent_location,
 // -------------------------------------------------------------------
 
 bool Parser::ParseLabel(FieldDescriptorProto::Label* label,
+                        const LocationRecorder& field_location,
                         const FileDescriptorProto* containing_file) {
+  if (!LookingAt("optional") && !LookingAt("repeated") && !LookingAt("required")) {
+    return false;
+  }
+  LocationRecorder location(field_location,
+                            FieldDescriptorProto::kLabelFieldNumber);
   if (TryConsume("optional")) {
     *label = FieldDescriptorProto::LABEL_OPTIONAL;
-    return true;
   } else if (TryConsume("repeated")) {
     *label = FieldDescriptorProto::LABEL_REPEATED;
-    return true;
-  } else if (TryConsume("required")) {
+  } else {
+    Consume("required");
     *label = FieldDescriptorProto::LABEL_REQUIRED;
-    return true;
   }
-  return false;
+  return true;
 }
 
 bool Parser::ParseType(FieldDescriptorProto::Type* type,
diff --git a/src/google/protobuf/compiler/parser.h b/src/google/protobuf/compiler/parser.h
index 9e2dc5f53204..45d433dc2b31 100644
--- a/src/google/protobuf/compiler/parser.h
+++ b/src/google/protobuf/compiler/parser.h
@@ -440,6 +440,7 @@ class PROTOBUF_EXPORT Parser {
   // Parse "required", "optional", or "repeated" and fill in "label"
   // with the value. Returns true if such a label is consumed.
   bool ParseLabel(FieldDescriptorProto::Label* label,
+                  const LocationRecorder& field_location,
                   const FileDescriptorProto* containing_file);
 
   // Parse a type name and fill in "type" (if it is a primitive) or
diff --git a/src/google/protobuf/compiler/parser_unittest.cc b/src/google/protobuf/compiler/parser_unittest.cc
index ccf020b5fb5d..2070ab9052da 100644
--- a/src/google/protobuf/compiler/parser_unittest.cc
+++ b/src/google/protobuf/compiler/parser_unittest.cc
@@ -2808,6 +2808,35 @@ TEST_F(SourceInfoTest, Fields) {
   EXPECT_TRUE(HasSpan(file_.message_type(0), "name"));
 }
 
+TEST_F(SourceInfoTest, Proto3Fields) {
+  EXPECT_TRUE(
+      Parse("syntax = \"proto3\";\n"
+            "message Foo {\n"
+            "  $a$int32$b$ $c$bar$d$ = $e$1$f$;$g$\n"
+            "  $h$repeated$i$ $j$X.Y$k$ $l$baz$m$ = $n$2$o$;$p$\n"
+            "}\n"));
+
+  const FieldDescriptorProto& field1 = file_.message_type(0).field(0);
+  const FieldDescriptorProto& field2 = file_.message_type(0).field(1);
+
+  EXPECT_TRUE(HasSpan('a', 'g', field1));
+  EXPECT_TRUE(HasSpan('a', 'b', field1, "type"));
+  EXPECT_TRUE(HasSpan('c', 'd', field1, "name"));
+  EXPECT_TRUE(HasSpan('e', 'f', field1, "number"));
+
+  EXPECT_TRUE(HasSpan('h', 'p', field2));
+  EXPECT_TRUE(HasSpan('h', 'i', field2, "label"));
+  EXPECT_TRUE(HasSpan('j', 'k', field2, "type_name"));
+  EXPECT_TRUE(HasSpan('l', 'm', field2, "name"));
+  EXPECT_TRUE(HasSpan('n', 'o', field2, "number"));
+
+  // Ignore these.
+  EXPECT_TRUE(HasSpan(file_));
+  EXPECT_TRUE(HasSpan(file_, "syntax"));
+  EXPECT_TRUE(HasSpan(file_.message_type(0)));
+  EXPECT_TRUE(HasSpan(file_.message_type(0), "name"));
+}
+
 TEST_F(SourceInfoTest, Extensions) {
   EXPECT_TRUE(
       Parse("$a$extend $b$Foo$c$ {\n"