diff --git a/org.lflang/src/org/lflang/generator/TargetTypes.java b/org.lflang/src/org/lflang/generator/TargetTypes.java
index c667d45a20..8e72c2a3f0 100644
--- a/org.lflang/src/org/lflang/generator/TargetTypes.java
+++ b/org.lflang/src/org/lflang/generator/TargetTypes.java
@@ -163,7 +163,7 @@ default String getTargetType(InferredType type) {
         } else if (type.isVariableSizeList) {
             return getTargetVariableSizeListType(type.baseType());
         }
-        return type.toText();
+        return type.toOriginalText();
     }
 
     /**
diff --git a/org.lflang/src/org/lflang/generator/ts/TSParameterPreambleGenerator.kt b/org.lflang/src/org/lflang/generator/ts/TSParameterPreambleGenerator.kt
index 5b1e032331..02380fa9fd 100644
--- a/org.lflang/src/org/lflang/generator/ts/TSParameterPreambleGenerator.kt
+++ b/org.lflang/src/org/lflang/generator/ts/TSParameterPreambleGenerator.kt
@@ -126,7 +126,7 @@ class TSParameterPreambleGenerator(
             var customArgType: String? = null
             var customTypeLabel: String? = null
 
-            val paramType = parameter.type.id
+            val paramType = getTargetType(parameter)
             if (paramType == "string") {
                 mainParameters.add(parameter)
                 customArgType = "String";