diff --git a/src/core/CompileCall.go b/src/core/CompileCall.go
index e9c94b2..3d4ad40 100644
--- a/src/core/CompileCall.go
+++ b/src/core/CompileCall.go
@@ -52,17 +52,6 @@ func (f *Function) CompileCall(root *expression.Expression) ([]types.Type, error
 	fn, exists = f.All.Functions[pkg+"."+name]
 
 	if !exists {
-		typ := types.ByName(name, f.Package, f.All.Structs)
-
-		if typ != nil {
-			if len(root.Children) != 2 {
-				return nil, errors.New(&errors.ParameterCountMismatch{Function: name, Count: len(root.Children), ExpectedCount: 1}, f.File, nameNode.Token.End())
-			}
-
-			_, err := f.ExpressionToRegister(root.Children[1], f.CPU.Output[0])
-			return []types.Type{typ}, err
-		}
-
 		return nil, errors.New(&errors.UnknownFunction{Name: name}, f.File, nameNode.Token.Position)
 	}
 
diff --git a/src/core/EvaluateCall.go b/src/core/EvaluateCall.go
index 6defe4f..ad092a0 100644
--- a/src/core/EvaluateCall.go
+++ b/src/core/EvaluateCall.go
@@ -1,12 +1,56 @@
 package core
 
 import (
+	"git.urbach.dev/cli/q/src/errors"
 	"git.urbach.dev/cli/q/src/eval"
 	"git.urbach.dev/cli/q/src/expression"
+	"git.urbach.dev/cli/q/src/token"
+	"git.urbach.dev/cli/q/src/types"
 )
 
 // EvaluateCall evaluates a function call.
-func (f *Function) EvaluateCall(expr *expression.Expression) (*eval.Register, error) {
+func (f *Function) EvaluateCall(expr *expression.Expression) (eval.Value, error) {
+	if expr.Children[0].Token.Kind == token.Identifier {
+		nameNode := expr.Children[0]
+		name := nameNode.String(f.File.Bytes)
+		typ := types.ByName(name, f.Package, f.All.Structs)
+
+		if typ != nil {
+			if len(expr.Children) != 2 {
+				return nil, errors.New(&errors.ParameterCountMismatch{Function: name, Count: len(expr.Children), ExpectedCount: 1}, f.File, nameNode.Token.End())
+			}
+
+			value, err := f.Evaluate(expr.Children[1])
+
+			if err != nil {
+				return nil, err
+			}
+
+			switch value := value.(type) {
+			case *eval.Register:
+				if value.IsAlive() {
+					value = &eval.Register{
+						Typ:      typ,
+						Register: value.Register,
+						Alive:    value.Alive,
+					}
+
+					return value, nil
+				}
+
+				value.Typ = typ
+			case *eval.Number:
+				value.Typ = typ
+			case *eval.Memory:
+				value.Typ = typ
+			case *eval.Label:
+				value.Typ = typ
+			}
+
+			return value, nil
+		}
+	}
+
 	typ, err := f.CompileCall(expr)
 
 	if err != nil {
diff --git a/src/core/ExpressionToRegister.go b/src/core/ExpressionToRegister.go
index bd40f05..1efbfa8 100644
--- a/src/core/ExpressionToRegister.go
+++ b/src/core/ExpressionToRegister.go
@@ -28,8 +28,8 @@ func (f *Function) ExpressionToRegister(node *expression.Expression, register cp
 	}
 
 	switch node.Token.Kind {
-	case token.Array:
-		value, err := f.EvaluateArray(node)
+	case token.Call:
+		value, err := f.EvaluateCall(node)
 
 		if err != nil {
 			return nil, err
@@ -48,8 +48,8 @@ func (f *Function) ExpressionToRegister(node *expression.Expression, register cp
 		f.ValueToRegister(value, register)
 		return value.Type(), nil
 
-	case token.Call:
-		value, err := f.EvaluateCall(node)
+	case token.Array:
+		value, err := f.EvaluateArray(node)
 
 		if err != nil {
 			return nil, err