diff --git a/include/flatbuffers/idl.h b/include/flatbuffers/idl.h
index 6bec05afd..34441750f 100644
--- a/include/flatbuffers/idl.h
+++ b/include/flatbuffers/idl.h
@@ -317,7 +317,7 @@ struct EnumVal {
 struct EnumDef : public Definition {
   EnumDef() : is_union(false), uses_type_aliases(false) {}
 
-  EnumVal *ReverseLookup(int enum_idx, bool skip_union_default = true) {
+  EnumVal *ReverseLookup(int64_t enum_idx, bool skip_union_default = true) {
     for (auto it = vals.vec.begin() +
                    static_cast<int>(is_union && skip_union_default);
          it != vals.vec.end(); ++it) {
diff --git a/src/idl_gen_cpp.cpp b/src/idl_gen_cpp.cpp
index e497a9bab..15f2f38c2 100644
--- a/src/idl_gen_cpp.cpp
+++ b/src/idl_gen_cpp.cpp
@@ -1295,7 +1295,7 @@ class CppGenerator : public BaseGenerator {
   std::string GetDefaultScalarValue(const FieldDef &field) {
     if (field.value.type.enum_def && IsScalar(field.value.type.base_type)) {
       auto ev = field.value.type.enum_def->ReverseLookup(
-          static_cast<int>(StringToInt(field.value.constant.c_str())), false);
+          StringToInt(field.value.constant.c_str()), false);
       if (ev) {
         return WrapInNameSpace(field.value.type.enum_def->defined_namespace,
                                GetEnumValUse(*field.value.type.enum_def, *ev));
diff --git a/src/idl_gen_js.cpp b/src/idl_gen_js.cpp
index 42647cbaf..8c7e713a8 100644
--- a/src/idl_gen_js.cpp
+++ b/src/idl_gen_js.cpp
@@ -371,7 +371,7 @@ class JsGenerator : public BaseGenerator {
   std::string GenDefaultValue(const Value &value, const std::string &context) {
     if (value.type.enum_def) {
       if (auto val = value.type.enum_def->ReverseLookup(
-              atoi(value.constant.c_str()), false)) {
+              StringToInt(value.constant.c_str()), false)) {
         if (lang_.language == IDLOptions::kTs) {
           return GenPrefixedTypeName(WrapInNameSpace(*value.type.enum_def),
                                      value.type.enum_def->file) +
diff --git a/src/idl_gen_php.cpp b/src/idl_gen_php.cpp
index 101f3c28f..08250e98c 100644
--- a/src/idl_gen_php.cpp
+++ b/src/idl_gen_php.cpp
@@ -876,7 +876,7 @@ class PhpGenerator : public BaseGenerator {
   std::string GenDefaultValue(const Value &value) {
     if (value.type.enum_def) {
       if (auto val = value.type.enum_def->ReverseLookup(
-              atoi(value.constant.c_str()), false)) {
+              StringToInt(value.constant.c_str()), false)) {
         return WrapInNameSpace(*value.type.enum_def) + "::" + val->name;
       }
     }
diff --git a/src/idl_gen_text.cpp b/src/idl_gen_text.cpp
index 95165fd04..40afbf40e 100644
--- a/src/idl_gen_text.cpp
+++ b/src/idl_gen_text.cpp
@@ -51,7 +51,7 @@ bool Print(T val, Type type, int /*indent*/, Type * /*union_type*/,
            const IDLOptions &opts, std::string *_text) {
   std::string &text = *_text;
   if (type.enum_def && opts.output_enum_identifiers) {
-    auto enum_val = type.enum_def->ReverseLookup(static_cast<int>(val));
+    auto enum_val = type.enum_def->ReverseLookup(static_cast<int64_t>(val));
     if (enum_val) {
       text += "\"";
       text += enum_val->name;
diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index 39a96d11f..1a9f8b2e3 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -656,8 +656,8 @@ CheckedError Parser::ParseField(StructDef &struct_def) {
   if (type.enum_def &&
       !type.enum_def->is_union &&
       !type.enum_def->attributes.Lookup("bit_flags") &&
-      !type.enum_def->ReverseLookup(static_cast<int>(
-                                 StringToInt(field->value.constant.c_str())))) {
+      !type.enum_def->ReverseLookup(StringToInt(
+                                      field->value.constant.c_str()))) {
     return Error("default value of " + field->value.constant + " for field " +
                  name + " is not part of enum " + type.enum_def->name);
   }
@@ -668,8 +668,8 @@ CheckedError Parser::ParseField(StructDef &struct_def) {
 
   if (type.enum_def && IsScalar(type.base_type) && !struct_def.fixed &&
       !type.enum_def->attributes.Lookup("bit_flags") &&
-      !type.enum_def->ReverseLookup(
-          static_cast<int>(StringToInt(field->value.constant.c_str()))))
+      !type.enum_def->ReverseLookup(StringToInt(
+                                      field->value.constant.c_str())))
     Warning("enum " + type.enum_def->name +
             " does not have a declaration for this field\'s default of " +
             field->value.constant);