diff --git a/aidl_const_expressions.cpp b/aidl_const_expressions.cpp
index b97889d..b9b62ea 100644
--- a/aidl_const_expressions.cpp
+++ b/aidl_const_expressions.cpp
@@ -242,12 +242,6 @@
   return false;
 }
 
-static bool isValidLiteralChar(char c) {
-  return !(c <= 0x1f ||  // control characters are < 0x20
-           c >= 0x7f ||  // DEL is 0x7f
-           c == '\\');   // Disallow backslashes for future proofing.
-}
-
 bool ParseFloating(std::string_view sv, double* parsed) {
   // float literal should be parsed successfully.
   android::base::ConsumeSuffix(&sv, "f");
@@ -338,6 +332,9 @@
   if (name == "boolean") {
     return Boolean(location, false);
   }
+  if (name == "char") {
+    return Character(location, "'\\0'");  // literal to be used in backends
+  }
   if (name == "byte" || name == "int" || name == "long") {
     return Integral(location, "0");
   }
@@ -354,13 +351,9 @@
   return new AidlConstantValue(location, Type::BOOLEAN, value ? "true" : "false");
 }
 
-AidlConstantValue* AidlConstantValue::Character(const AidlLocation& location, char value) {
-  const std::string explicit_value = string("'") + value + "'";
-  if (!isValidLiteralChar(value)) {
-    AIDL_ERROR(location) << "Invalid character literal " << value;
-    return new AidlConstantValue(location, Type::ERROR, explicit_value);
-  }
-  return new AidlConstantValue(location, Type::CHARACTER, explicit_value);
+AidlConstantValue* AidlConstantValue::Character(const AidlLocation& location,
+                                                const std::string& value) {
+  return new AidlConstantValue(location, Type::CHARACTER, value);
 }
 
 AidlConstantValue* AidlConstantValue::Floating(const AidlLocation& location,
@@ -453,14 +446,6 @@
 }
 
 AidlConstantValue* AidlConstantValue::String(const AidlLocation& location, const string& value) {
-  for (size_t i = 0; i < value.length(); ++i) {
-    if (!isValidLiteralChar(value[i])) {
-      AIDL_ERROR(location) << "Found invalid character at index " << i << " in string constant '"
-                           << value << "'";
-      return new AidlConstantValue(location, Type::ERROR, value);
-    }
-  }
-
   return new AidlConstantValue(location, Type::STRING, value);
 }
 
@@ -1007,6 +992,8 @@
   return false;
 }
 
+// Constructor for integer(byte, int, long)
+// Keep parsed integer & literal
 AidlConstantValue::AidlConstantValue(const AidlLocation& location, Type parsed_type,
                                      int64_t parsed_value, const string& checked_value)
     : AidlNode(location),
@@ -1018,6 +1005,8 @@
   AIDL_FATAL_IF(type_ != Type::INT8 && type_ != Type::INT32 && type_ != Type::INT64, location);
 }
 
+// Constructor for non-integer(String, char, boolean, float, double)
+// Keep literal as it is. (e.g. String literal has double quotes at both ends)
 AidlConstantValue::AidlConstantValue(const AidlLocation& location, Type type,
                                      const string& checked_value)
     : AidlNode(location),
@@ -1037,6 +1026,7 @@
   }
 }
 
+// Constructor for array
 AidlConstantValue::AidlConstantValue(const AidlLocation& location, Type type,
                                      std::unique_ptr<vector<unique_ptr<AidlConstantValue>>> values,
                                      const std::string& value)
diff --git a/aidl_language.h b/aidl_language.h
index e0c28a0..931c606 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -608,7 +608,7 @@
     } else if constexpr (is_one_of<T, int8_t, int32_t, int64_t>::value) {
       AIDL_FATAL_IF(final_type_ < Type::INT8 && final_type_ > Type::INT64, this);
       return static_cast<T>(final_value_);
-    } else if constexpr (std::is_same<T, char>::value) {
+    } else if constexpr (std::is_same<T, char16_t>::value) {
       AIDL_FATAL_IF(final_type_ != Type::CHARACTER, this);
       return final_string_value_.at(1);  // unquote '
     } else if constexpr (std::is_same<T, bool>::value) {
@@ -633,9 +633,9 @@
   static AidlConstantValue* Default(const AidlTypeSpecifier& specifier);
 
   static AidlConstantValue* Boolean(const AidlLocation& location, bool value);
-  static AidlConstantValue* Character(const AidlLocation& location, char value);
+  static AidlConstantValue* Character(const AidlLocation& location, const std::string& value);
   // example: 123, -5498, maybe any size
-  static AidlConstantValue* Integral(const AidlLocation& location, const string& value);
+  static AidlConstantValue* Integral(const AidlLocation& location, const std::string& value);
   static AidlConstantValue* Floating(const AidlLocation& location, const std::string& value);
   static AidlConstantValue* Array(const AidlLocation& location,
                                   std::unique_ptr<vector<unique_ptr<AidlConstantValue>>> values);
diff --git a/aidl_language_l.ll b/aidl_language_l.ll
index e43ef45..2b63b82 100644
--- a/aidl_language_l.ll
+++ b/aidl_language_l.ll
@@ -142,9 +142,8 @@
 {identifier}          { yylval->token = new AidlToken(yytext, comments);
                         return yy::parser::token::IDENTIFIER;
                       }
-'.'                   { yylval->character = yytext[1];
-                        return yy::parser::token::CHARVALUE;
-                      }
+'.'                   { yylval->token = new AidlToken(yytext, comments);
+                        return yy::parser::token::CHARVALUE; }
 {intvalue}            { yylval->token = new AidlToken(yytext, comments);
                         return yy::parser::token::INTVALUE; }
 {floatvalue}          { yylval->token = new AidlToken(yytext, comments);
diff --git a/aidl_language_y.yy b/aidl_language_y.yy
index ab3e479..079bda6 100644
--- a/aidl_language_y.yy
+++ b/aidl_language_y.yy
@@ -96,7 +96,6 @@
     std::vector<std::unique_ptr<AidlDefinedType>>* declarations;
 }
 
-%destructor { } <character>
 %destructor { } <direction>
 %destructor { delete ($$); } <*>
 
@@ -112,7 +111,7 @@
 %token<token> UNION "union"
 %token<token> CONST "const"
 
-%token<character> CHARVALUE "char literal"
+%token<token> CHARVALUE "char literal"
 %token<token> FLOATVALUE "float literal"
 %token<token> HEXVALUE "hex literal"
 %token<token> INTVALUE "int literal"
@@ -395,7 +394,10 @@
 const_expr
  : TRUE_LITERAL { $$ = AidlConstantValue::Boolean(loc(@1), true); }
  | FALSE_LITERAL { $$ = AidlConstantValue::Boolean(loc(@1), false); }
- | CHARVALUE { $$ = AidlConstantValue::Character(loc(@1), $1); }
+ | CHARVALUE {
+    $$ = AidlConstantValue::Character(loc(@1), $1->GetText());
+    delete $1;
+  }
  | INTVALUE {
     $$ = AidlConstantValue::Integral(loc(@1), $1->GetText());
     if ($$ == nullptr) {
diff --git a/aidl_unittest.cpp b/aidl_unittest.cpp
index 7ea8c17..4621dd8 100644
--- a/aidl_unittest.cpp
+++ b/aidl_unittest.cpp
@@ -1025,7 +1025,7 @@
   using Ptr = unique_ptr<AidlConstantValue>;
   const AidlLocation& loc = AIDL_LOCATION_HERE;
 
-  EXPECT_EQ('c', Ptr(AidlConstantValue::Character(loc, 'c'))->EvaluatedValue<char>());
+  EXPECT_EQ('c', Ptr(AidlConstantValue::Character(loc, "'c'"))->EvaluatedValue<char16_t>());
   EXPECT_EQ("abc", Ptr(AidlConstantValue::String(loc, "\"abc\""))->EvaluatedValue<string>());
   EXPECT_FLOAT_EQ(1.0f, Ptr(AidlConstantValue::Floating(loc, "1.0f"))->EvaluatedValue<float>());
   EXPECT_EQ(true, Ptr(AidlConstantValue::Boolean(loc, true))->EvaluatedValue<bool>());
@@ -1043,6 +1043,14 @@
       Ptr(AidlConstantValue::Array(loc, std::move(values)))->EvaluatedValue<vector<string>>());
 }
 
+TEST_F(AidlTest, AidlConstantCharacterDefault) {
+  AidlTypeSpecifier char_type(AIDL_LOCATION_HERE, "char", false, nullptr, {});
+  auto default_value = unique_ptr<AidlConstantValue>(AidlConstantValue::Default(char_type));
+  EXPECT_EQ("'\\0'", default_value->ValueString(char_type, cpp::ConstantValueDecorator));
+  EXPECT_EQ("'\\0'", default_value->ValueString(char_type, ndk::ConstantValueDecorator));
+  EXPECT_EQ("'\\0'", default_value->ValueString(char_type, java::ConstantValueDecorator));
+}
+
 TEST_P(AidlTest, FailOnManyDefinedTypes) {
   AidlError error;
   const string expected_stderr =