diff --git a/src/google/protobuf/compiler/cpp/cpp_parse_function_generator.cc b/src/google/protobuf/compiler/cpp/cpp_parse_function_generator.cc
index 0f198e77318ee..8b181206de04d 100644
--- a/src/google/protobuf/compiler/cpp/cpp_parse_function_generator.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_parse_function_generator.cc
@@ -859,7 +859,8 @@ void ParseFunctionGenerator::GenerateFieldBody(
               field->number());
         }
       } else {
-        std::string size = (field->type() == FieldDescriptor::TYPE_SINT32 ||
+        std::string size = (field->type() == FieldDescriptor::TYPE_INT32  ||
+                            field->type() == FieldDescriptor::TYPE_SINT32 ||
                             field->type() == FieldDescriptor::TYPE_UINT32)
                                ? "32"
                                : "64";
diff --git a/src/google/protobuf/compiler/plugin.pb.cc b/src/google/protobuf/compiler/plugin.pb.cc
index c11b3f8423fc2..f4c1a1f8b7093 100644
--- a/src/google/protobuf/compiler/plugin.pb.cc
+++ b/src/google/protobuf/compiler/plugin.pb.cc
@@ -318,7 +318,7 @@ const char* Version::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::in
       case 1:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8)) {
           _Internal::set_has_major(&has_bits);
-          major_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          major_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -327,7 +327,7 @@ const char* Version::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::in
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
           _Internal::set_has_minor(&has_bits);
-          minor_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          minor_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -336,7 +336,7 @@ const char* Version::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::in
       case 3:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 24)) {
           _Internal::set_has_patch(&has_bits);
-          patch_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          patch_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
diff --git a/src/google/protobuf/descriptor.pb.cc b/src/google/protobuf/descriptor.pb.cc
index 7aa60e80fd05f..0b057cd8624bb 100644
--- a/src/google/protobuf/descriptor.pb.cc
+++ b/src/google/protobuf/descriptor.pb.cc
@@ -1727,7 +1727,7 @@ const char* FileDescriptorProto::_InternalParse(const char* ptr, ::PROTOBUF_NAME
           ptr -= 1;
           do {
             ptr += 1;
-            _internal_add_public_dependency(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr));
+            _internal_add_public_dependency(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr));
             CHK_(ptr);
             if (!ctx->DataAvailable(ptr)) break;
           } while (::PROTOBUF_NAMESPACE_ID::internal::ExpectTag<80>(ptr));
@@ -1743,7 +1743,7 @@ const char* FileDescriptorProto::_InternalParse(const char* ptr, ::PROTOBUF_NAME
           ptr -= 1;
           do {
             ptr += 1;
-            _internal_add_weak_dependency(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr));
+            _internal_add_weak_dependency(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr));
             CHK_(ptr);
             if (!ctx->DataAvailable(ptr)) break;
           } while (::PROTOBUF_NAMESPACE_ID::internal::ExpectTag<88>(ptr));
@@ -2219,7 +2219,7 @@ const char* DescriptorProto_ExtensionRange::_InternalParse(const char* ptr, ::PR
       case 1:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8)) {
           _Internal::set_has_start(&has_bits);
-          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -2228,7 +2228,7 @@ const char* DescriptorProto_ExtensionRange::_InternalParse(const char* ptr, ::PR
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
           _Internal::set_has_end(&has_bits);
-          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -2485,7 +2485,7 @@ const char* DescriptorProto_ReservedRange::_InternalParse(const char* ptr, ::PRO
       case 1:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8)) {
           _Internal::set_has_start(&has_bits);
-          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -2494,7 +2494,7 @@ const char* DescriptorProto_ReservedRange::_InternalParse(const char* ptr, ::PRO
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
           _Internal::set_has_end(&has_bits);
-          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -3599,7 +3599,7 @@ const char* FieldDescriptorProto::_InternalParse(const char* ptr, ::PROTOBUF_NAM
       case 3:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 24)) {
           _Internal::set_has_number(&has_bits);
-          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -3666,7 +3666,7 @@ const char* FieldDescriptorProto::_InternalParse(const char* ptr, ::PROTOBUF_NAM
       case 9:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 72)) {
           _Internal::set_has_oneof_index(&has_bits);
-          oneof_index_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          oneof_index_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -4385,7 +4385,7 @@ const char* EnumDescriptorProto_EnumReservedRange::_InternalParse(const char* pt
       case 1:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8)) {
           _Internal::set_has_start(&has_bits);
-          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          start_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -4394,7 +4394,7 @@ const char* EnumDescriptorProto_EnumReservedRange::_InternalParse(const char* pt
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
           _Internal::set_has_end(&has_bits);
-          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -5034,7 +5034,7 @@ const char* EnumValueDescriptorProto::_InternalParse(const char* ptr, ::PROTOBUF
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
           _Internal::set_has_number(&has_bits);
-          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -9833,7 +9833,7 @@ const char* SourceCodeInfo_Location::_InternalParse(const char* ptr, ::PROTOBUF_
           ptr = ::PROTOBUF_NAMESPACE_ID::internal::PackedInt32Parser(_internal_mutable_path(), ptr, ctx);
           CHK_(ptr);
         } else if (static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8) {
-          _internal_add_path(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr));
+          _internal_add_path(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr));
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -9844,7 +9844,7 @@ const char* SourceCodeInfo_Location::_InternalParse(const char* ptr, ::PROTOBUF_
           ptr = ::PROTOBUF_NAMESPACE_ID::internal::PackedInt32Parser(_internal_mutable_span(), ptr, ctx);
           CHK_(ptr);
         } else if (static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16) {
-          _internal_add_span(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr));
+          _internal_add_span(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr));
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -10405,7 +10405,7 @@ const char* GeneratedCodeInfo_Annotation::_InternalParse(const char* ptr, ::PROT
           ptr = ::PROTOBUF_NAMESPACE_ID::internal::PackedInt32Parser(_internal_mutable_path(), ptr, ctx);
           CHK_(ptr);
         } else if (static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8) {
-          _internal_add_path(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr));
+          _internal_add_path(::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr));
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -10426,7 +10426,7 @@ const char* GeneratedCodeInfo_Annotation::_InternalParse(const char* ptr, ::PROT
       case 3:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 24)) {
           _Internal::set_has_begin(&has_bits);
-          begin_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          begin_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -10435,7 +10435,7 @@ const char* GeneratedCodeInfo_Annotation::_InternalParse(const char* ptr, ::PROT
       case 4:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 32)) {
           _Internal::set_has_end(&has_bits);
-          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          end_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
diff --git a/src/google/protobuf/duration.pb.cc b/src/google/protobuf/duration.pb.cc
index edf91fb24f583..6a3e9efe9cf21 100644
--- a/src/google/protobuf/duration.pb.cc
+++ b/src/google/protobuf/duration.pb.cc
@@ -157,7 +157,7 @@ const char* Duration::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::i
       // int32 nanos = 2;
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
-          nanos_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          nanos_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
diff --git a/src/google/protobuf/timestamp.pb.cc b/src/google/protobuf/timestamp.pb.cc
index ed0a6eb58af20..6918b49f1a7c7 100644
--- a/src/google/protobuf/timestamp.pb.cc
+++ b/src/google/protobuf/timestamp.pb.cc
@@ -157,7 +157,7 @@ const char* Timestamp::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::
       // int32 nanos = 2;
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
-          nanos_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          nanos_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
diff --git a/src/google/protobuf/type.pb.cc b/src/google/protobuf/type.pb.cc
index 8ef4ba115d41c..60e27b7ad092a 100644
--- a/src/google/protobuf/type.pb.cc
+++ b/src/google/protobuf/type.pb.cc
@@ -847,7 +847,7 @@ const char* Field::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::inte
       // int32 number = 3;
       case 3:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 24)) {
-          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -875,7 +875,7 @@ const char* Field::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::inte
       // int32 oneof_index = 7;
       case 7:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 56)) {
-          oneof_index_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          oneof_index_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
@@ -1646,7 +1646,7 @@ const char* EnumValue::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::
       // int32 number = 2;
       case 2:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 16)) {
-          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          number_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;
diff --git a/src/google/protobuf/wrappers.pb.cc b/src/google/protobuf/wrappers.pb.cc
index d98f54a331f2e..a3452f6e9a975 100644
--- a/src/google/protobuf/wrappers.pb.cc
+++ b/src/google/protobuf/wrappers.pb.cc
@@ -1026,7 +1026,7 @@ const char* Int32Value::_InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID:
       // int32 value = 1;
       case 1:
         if (PROTOBUF_PREDICT_TRUE(static_cast<::PROTOBUF_NAMESPACE_ID::uint8>(tag) == 8)) {
-          value_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          value_ = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint32(&ptr);
           CHK_(ptr);
         } else
           goto handle_unusual;