diff --git a/conformance/binary_json_conformance_suite.cc b/conformance/binary_json_conformance_suite.cc
index 239db3b7afc97..a915c29263807 100644
--- a/conformance/binary_json_conformance_suite.cc
+++ b/conformance/binary_json_conformance_suite.cc
@@ -3334,6 +3334,10 @@ void BinaryAndJsonConformanceSuite::RunJsonTestsForValue() {
         return value.empty();
       },
       true);
+  ExpectSerializeFailureForJson("ValueRejectNanNumberValue", RECOMMENDED,
+                                "optional_value: { number_value: nan}");
+  ExpectSerializeFailureForJson("ValueRejectInfNumberValue", RECOMMENDED,
+                                "optional_value: { number_value: inf}");
 }
 
 void BinaryAndJsonConformanceSuite::RunJsonTestsForAny() {
diff --git a/conformance/failure_list_ruby.txt b/conformance/failure_list_ruby.txt
index 3c744391cf754..8eb63b9a7d4f2 100644
--- a/conformance/failure_list_ruby.txt
+++ b/conformance/failure_list_ruby.txt
@@ -58,3 +58,5 @@ Recommended.Proto3.ProtobufInput.ValidDataRepeated.UINT32.PackedInput.UnpackedOu
 Recommended.Proto3.ProtobufInput.ValidDataRepeated.UINT32.UnpackedInput.UnpackedOutput.ProtobufOutput
 Recommended.Proto3.ProtobufInput.ValidDataRepeated.UINT64.PackedInput.UnpackedOutput.ProtobufOutput
 Recommended.Proto3.ProtobufInput.ValidDataRepeated.UINT64.UnpackedInput.UnpackedOutput.ProtobufOutput
+Recommended.ValueRejectInfNumberValue.JsonOutput
+Recommended.ValueRejectNanNumberValue.JsonOutput
diff --git a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
index 992980b0dc730..96bc38898f2d6 100644
--- a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
+++ b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
@@ -51,7 +51,6 @@
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
-import com.google.protobuf.Descriptors.FieldDescriptor.Type;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
 import com.google.protobuf.DoubleValue;
@@ -966,7 +965,16 @@ private void printValue(MessageOrBuilder message) throws IOException {
         throw new InvalidProtocolBufferException("Invalid Value type.");
       }
       for (Map.Entry<FieldDescriptor, Object> entry : fields.entrySet()) {
-        printSingleFieldValue(entry.getKey(), entry.getValue());
+        FieldDescriptor field = entry.getKey();
+        if (field.getType() == FieldDescriptor.Type.DOUBLE) {
+          Double doubleValue = (Double) entry.getValue();
+          if (doubleValue.isNaN() || doubleValue.isInfinite()) {
+            throw new IllegalArgumentException(
+                "google.protobuf.Value cannot encode double values for "
+                + "infinity or nan, because they would be parsed as a string.");
+          }
+        }
+        printSingleFieldValue(field, entry.getValue());
       }
     }
 
@@ -1683,7 +1691,7 @@ private void mergeMapField(FieldDescriptor field, JsonElement json, Message.Buil
         Object key = parseFieldValue(keyField, new JsonPrimitive(entry.getKey()), entryBuilder);
         Object value = parseFieldValue(valueField, entry.getValue(), entryBuilder);
         if (value == null) {
-          if (ignoringUnknownFields && valueField.getType() == Type.ENUM) {
+          if (ignoringUnknownFields && valueField.getType() == FieldDescriptor.Type.ENUM) {
             continue;
           } else {
             throw new InvalidProtocolBufferException("Map value cannot be null.");
@@ -1724,7 +1732,7 @@ private void mergeRepeatedField(
       for (int i = 0; i < array.size(); ++i) {
         Object value = parseFieldValue(field, array.get(i), builder);
         if (value == null) {
-          if (ignoringUnknownFields && field.getType() == Type.ENUM) {
+          if (ignoringUnknownFields && field.getType() == FieldDescriptor.Type.ENUM) {
             continue;
           } else {
             throw new InvalidProtocolBufferException(
diff --git a/src/google/protobuf/json/internal/unparser.cc b/src/google/protobuf/json/internal/unparser.cc
index 5bda3dbf039f5..85fa403665522 100644
--- a/src/google/protobuf/json/internal/unparser.cc
+++ b/src/google/protobuf/json/internal/unparser.cc
@@ -34,6 +34,7 @@
 #include <complex>
 #include <cstdint>
 #include <cstring>
+#include <limits>
 #include <memory>
 #include <sstream>
 #include <string>
@@ -489,6 +490,17 @@ absl::Status WriteValue(JsonWriter& writer, const Msg<Traits>& msg,
   if (Traits::GetSize(number_field, msg) > 0) {
     auto x = Traits::GetDouble(number_field, msg);
     RETURN_IF_ERROR(x.status());
+    if (std::isnan(*x)) {
+      return absl::InvalidArgumentError(
+          "google.protobuf.Value cannot encode double values for nan, "
+          "because it would be parsed as a string");
+    }
+    if (*x == std::numeric_limits<double>::infinity() ||
+        *x == -std::numeric_limits<double>::infinity()) {
+      return absl::InvalidArgumentError(
+          "google.protobuf.Value cannot encode double values for "
+          "infinity, because it would be parsed as a string");
+    }
     writer.Write(*x);
     return absl::OkStatus();
   }