diff --git a/src/google/protobuf/compiler/parser_unittest.cc b/src/google/protobuf/compiler/parser_unittest.cc
index 1b74d774b4..4a5b7c9286 100644
--- a/src/google/protobuf/compiler/parser_unittest.cc
+++ b/src/google/protobuf/compiler/parser_unittest.cc
@@ -2231,7 +2231,7 @@ TEST_F(ParserValidationErrorTest, EnumValueAliasError) {
       "}\n",
       "2:8: \"BAZ\" uses the same enum value as \"BAR\". If this is "
       "intended, set 'option allow_alias = true;' to the enum "
-      "definition.\n");
+      "definition. The next available enum value is 2.\n");
 }
 
 TEST_F(ParserValidationErrorTest, ExplicitlyMapEntryError) {
diff --git a/src/google/protobuf/descriptor.cc b/src/google/protobuf/descriptor.cc
index 2750653ee8..5242da004e 100644
--- a/src/google/protobuf/descriptor.cc
+++ b/src/google/protobuf/descriptor.cc
@@ -7382,12 +7382,25 @@ void DescriptorBuilder::ValidateEnumOptions(EnumDescriptor* enm,
         if (!enm->options().allow_alias()) {
           // Generate error if duplicated enum values are explicitly disallowed.
           auto make_error = [&] {
-            return absl::StrCat(
+            // Find the next free number.
+            absl::flat_hash_set<int64_t> used;
+            for (int j = 0; j < enm->value_count(); ++j) {
+              used.insert(enm->value(j)->number());
+            }
+            int64_t next_value = static_cast<int64_t>(enum_value->number()) + 1;
+            while (used.contains(next_value)) ++next_value;
+
+            std::string error = absl::StrCat(
                 "\"", enum_value->full_name(),
                 "\" uses the same enum value as \"",
                 insert_result.first->second,
                 "\". If this is intended, set "
                 "'option allow_alias = true;' to the enum definition.");
+            if (next_value < std::numeric_limits<int32_t>::max()) {
+              absl::StrAppend(&error, " The next available enum value is ",
+                              next_value, ".");
+            }
+            return error;
           };
           AddError(enm->full_name(), proto.value(i),
                    DescriptorPool::ErrorCollector::NUMBER, make_error);
diff --git a/src/google/protobuf/descriptor_unittest.cc b/src/google/protobuf/descriptor_unittest.cc
index 36fa422852..ba00a44ca4 100644
--- a/src/google/protobuf/descriptor_unittest.cc
+++ b/src/google/protobuf/descriptor_unittest.cc
@@ -6087,6 +6087,35 @@ TEST_F(ValidationErrorTest, DisallowEnumAlias) {
       "foo.proto: Bar: NUMBER: "
       "\"ENUM_B\" uses the same enum value as \"ENUM_A\". "
       "If this is intended, set 'option allow_alias = true;' to the enum "
+      "definition. The next available enum value is 1.\n");
+
+  BuildFileWithErrors(
+      R"pb(
+        name: "foo.proto"
+        enum_type {
+          name: "Bar"
+          value { name: "ENUM_A" number: 10 }
+          value { name: "ENUM_B" number: 10 }
+          value { name: "ENUM_C" number: 11 }
+          value { name: "ENUM_D" number: 20 }
+        })pb",
+      "foo.proto: Bar: NUMBER: "
+      "\"ENUM_B\" uses the same enum value as \"ENUM_A\". "
+      "If this is intended, set 'option allow_alias = true;' to the enum "
+      "definition. The next available enum value is 12.\n");
+
+  BuildFileWithErrors(
+      absl::Substitute(R"pb(
+                         name: "foo.proto"
+                         enum_type {
+                           name: "Bar"
+                           value { name: "ENUM_A" number: $0 }
+                           value { name: "ENUM_B" number: $0 }
+                         })pb",
+                       std::numeric_limits<int32_t>::max()),
+      "foo.proto: Bar: NUMBER: "
+      "\"ENUM_B\" uses the same enum value as \"ENUM_A\". "
+      "If this is intended, set 'option allow_alias = true;' to the enum "
       "definition.\n");
 }