diff --git a/entity/expression.go b/entity/expression.go
index 92cff0b..0cd37dd 100644
--- a/entity/expression.go
+++ b/entity/expression.go
@@ -61,8 +61,9 @@ func (this *Declaration) String () string {
 type Call struct {
 	// Syntax
 	Pos       lexer.Position
-	Name      string       `parser:" '[' @Ident  "`
-	Arguments []Expression `parser:"     @@* ']' "`
+	Module    string       `parser:" (@Ident '::')? "`
+	Name      string       `parser:" '[' @Ident     "`
+	Arguments []Expression `parser:"     @@* ']'    "`
 
 	// Semantics
 	Function *Function
@@ -71,7 +72,11 @@ func (*Call) expression(){}
 func (*Call) statement(){}
 func (this *Call) Type () Type { return this.Function.Signature.Return }
 func (this *Call) String () string {
-	out := fmt.Sprint("[", this.Name)
+	out := ""
+	if this.Module != "" {
+		out += fmt.Sprint(this.Module, "::")
+	}
+	out += fmt.Sprint("[", this.Name)
 	for _, argument := range this.Arguments {
 		out += fmt.Sprint(" ", argument)
 	}
diff --git a/entity/type.go b/entity/type.go
index 1d330f8..4b5ea91 100644
--- a/entity/type.go
+++ b/entity/type.go
@@ -16,14 +16,21 @@ type Type interface {
 // TypeNamed refers to a user-defined or built in named type.
 type TypeNamed struct {
 	Pos lexer.Position
-	Name string `parser:" @TypeIdent "`
-	Type Type
+	Module string `parser:" (@Ident '::')? "`
+	Name   string `parser:" @TypeIdent "`
+	Type   Type
 }
 func (*TypeNamed) ty(){}
-func (this *TypeNamed) String () string { return this.Name }
+func (this *TypeNamed) String () string {
+	if this.Module == "" {
+		return this.Name
+	} else {
+		return fmt.Sprint(this.Module, "::", this.Name)
+	}
+}
 func (this *TypeNamed) Equals (ty Type) bool {
 	real, ok := ty.(*TypeNamed)
-	return ok && real.Name == this.Name
+	return ok && real.Name == this.Name && real.Module == this.Module
 }
 
 // TypePointer is a pointer to another type.
diff --git a/parser/parser_test.go b/parser/parser_test.go
index 0f05f51..4bfef18 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -191,3 +191,13 @@ File.[write size:Index nmemb:Index]: Index 'fwrite'
 [main]: Int 'main' = 0
 `)
 }
+
+func TestModuleNamespace (test *testing.T) {
+testString (test,
+// correct
+`[hello out:io::Writer] = ioutil::[writeString out 'hello']`,
+// input
+`
+[hello out:io::Writer] = ioutil::[writeString out 'hello']
+`)
+}
diff --git a/parser/tree.go b/parser/tree.go
index 67ae1c4..08cb808 100644
--- a/parser/tree.go
+++ b/parser/tree.go
@@ -33,7 +33,6 @@ var parser = participle.MustBuild[Tree] (
 		new(entity.MethodCall),
 		new(entity.MemberAccess),
 		new(entity.Declaration),
-		new(entity.Variable),
 		new(entity.Subscript),
 		new(entity.Slice),
 		new(entity.Length),
@@ -43,6 +42,7 @@ var parser = participle.MustBuild[Tree] (
 		new(entity.BitCast),
 		new(entity.Operation),
 		new(entity.Call),
+		new(entity.Variable),
 		new(entity.Block)),
 	participle.Union[entity.Statement] (
 		new(entity.LiteralInt),
@@ -58,7 +58,6 @@ var parser = participle.MustBuild[Tree] (
 		new(entity.MethodCall),
 		new(entity.MemberAccess),
 		new(entity.Declaration),
-		new(entity.Variable),
 		new(entity.Subscript),
 		new(entity.Slice),
 		new(entity.Length),
@@ -68,6 +67,7 @@ var parser = participle.MustBuild[Tree] (
 		new(entity.BitCast),
 		new(entity.Operation),
 		new(entity.Call),
+		new(entity.Variable),
 		new(entity.Block)),
 	participle.UseLookahead(participle.MaxLookahead),
 	participle.Lexer(flexer.NewDefinition()))