diff --git a/design/spec.md b/design/spec.md
index f45ac57..70bfd74 100644
--- a/design/spec.md
+++ b/design/spec.md
@@ -320,7 +320,7 @@ this without hand-writing a parser.
 ```
 <file>     -> (<typedef> | <function> | <method>)*
 <access>   -> "+" | "#" | "-"
-<typedef>  -> [<access>] <typeIdentifier> ":" <type>
+<typedef>  -> [<access>] <typeIdentifier> ":" <type> <constantDeclaration>*
 <function> -> [<access>] <signature> ["=" <expression>]
 <method>   -> [<access>] <typeIdentifier> "." <function>
 
@@ -330,7 +330,7 @@ this without hand-writing a parser.
         | <arrayType>
         | <structType>
         | <interfaceType>
-<namedType>     -> <typeIdentifier>
+<namedType>     -> [<identifier> "::"] <typeIdentifier>
 <pointerType>   -> "*" <type>
 <sliceType>     -> "*" ":" <type>
 <arrayType>     -> <intLiteral> ":" <type>
@@ -362,9 +362,10 @@ this without hand-writing a parser.
               | <break>
               | <return>
               | <assignment>
+              | <constant>
 <variable>     -> <identifier>
 <declaration>  -> <identifier> ":" <type>
-<call>         -> "[" <expression>+ "]"
+<call>         -> [<identifier> "::"] "[" <expression>+ "]"
 <subscript>    -> "[" "." <expression> <expression> "]"
 <slice>        -> "[" "\" <expression> <expression>? "/" <expression>? "]"
 <length>       -> "[" "#" <expression> "]"
@@ -386,6 +387,7 @@ this without hand-writing a parser.
 <break>        -> "[" "break" [<expression>] "]"
 <return>       -> "[" "return" [<expression>] "]"
 <assignment>   -> <expression> "=" <expression>
+<constant>     -> <namedType> "." <identifier>
 
 <intLiteral> -> /-?[1-9][0-9]*/
               | /-?0[0-7]*/
@@ -397,15 +399,16 @@ this without hand-writing a parser.
 <structLiteral>  -> "(." <member>* ")"
 <booleanLiteral> -> "true" | "false"
 
-<member>         -> <identifier> ":" <expression>
-<matchCase>      -> "|" <declaration> <expression>
-<switchCase>     -> "|" <expression> <expression>
-<defaultCase>    -> "*" <expression>
-<signature>      -> "[" <identifier> <declaration>* "]" [":" <type>]
-<identifier>     -> /[a-z][A-Za-z]*/
-<typeIdentifier> -> /[A-Z][A-Za-z]*/
-<operator>       -> "+"  | "++" | "-"  | "--" | "*"  | "/" | "%"
-                  | "!!" | "||" | "&&" | "^^"
-                  | "!"  | "|"  | "&"  | "^"  | "<<" | ">>"
-                  | "<"  | ">"  | "<=" | ">=" | "="
+<member>              -> <identifier> ":" <expression>
+<constantDeclaration> -> "|" <identifier> ["=" <expression>]
+<matchCase>           -> "|" <declaration> <expression>
+<switchCase>          -> "|" <expression> <expression>
+<defaultCase>         -> "*" <expression>
+<signature>           -> "[" <identifier> <declaration>* "]" [":" <type>]
+<identifier>          -> /[a-z][A-Za-z]*/
+<typeIdentifier>      -> /[A-Z][A-Za-z]*/
+<operator>            -> "+"  | "++" | "-"  | "--" | "*"  | "/" | "%"
+                       | "!!" | "||" | "&&" | "^^"
+                       | "!"  | "|"  | "&"  | "^"  | "<<" | ">>"
+                       | "<"  | ">"  | "<=" | ">=" | "="
 ```
diff --git a/entity/misc.go b/entity/misc.go
index 7708e61..956938b 100644
--- a/entity/misc.go
+++ b/entity/misc.go
@@ -267,5 +267,5 @@ type ConstantDeclaration struct {
 func (this *ConstantDeclaration) Position () errors.Position { return this.Pos }
 func (this *ConstantDeclaration) Type () Type { return this.Ty }
 func (this *ConstantDeclaration) String () string {
-	return fmt.Sprint("| ", this.Name, " ", this.Value)
+	return fmt.Sprint("| ", this.Name, " = ", this.Value)
 }
diff --git a/parser/fspl/parser_test.go b/parser/fspl/parser_test.go
index 0d18c0c..8ce6986 100644
--- a/parser/fspl/parser_test.go
+++ b/parser/fspl/parser_test.go
@@ -13,9 +13,9 @@ testString (test,
 - StructArray: 31:24:340920:(. x:Int y:Int)
 - String: *:U8
 + FileDescriptor: I32
-| stdin 0
-| stdout 1
-| stderr 2`,
+| stdin = 0
+| stdout = 1
+| stderr = 2`,
 // input
 `
 BasicInt: Int
@@ -34,9 +34,9 @@ StructArray: 31:24:340920:(.
 	y:Int)
 String: *:U8
 + FileDescriptor: I32
-| stdin  0
-| stdout 1
-| stderr 2
+| stdin  = 0
+| stdout = 1
+| stderr = 2
 `)
 }
 
diff --git a/parser/fspl/toplevel.go b/parser/fspl/toplevel.go
index c31875b..c7364c7 100644
--- a/parser/fspl/toplevel.go
+++ b/parser/fspl/toplevel.go
@@ -186,7 +186,8 @@ func (this *treeParser) parseConstantDeclaration () (*entity.ConstantDeclaration
 	declaration.Name = this.Value()
 	this.Next()
 
-	if this.Is(startTokensExpression...) {
+	if this.Is(lexer.Symbol) && this.ValueIs("=") {
+		this.Next()
 		value, err := this.parseExpression()
 		if err != nil { return nil, err }
 		declaration.Value = value