diff --git a/AlgebraicDataflowArchitectureModel/src/models/algebra/Field.java b/AlgebraicDataflowArchitectureModel/src/models/algebra/Field.java
index f51b3c4..6702d3f 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/algebra/Field.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/algebra/Field.java
@@ -14,7 +14,8 @@
 	}
 	
 	public Field(String name, Type type) {
-		super(name, type);
+		super(name);
+		symbol.setSignature(new Type[] {type});
 	}
 	
 	public Field(Symbol symbol) {
@@ -22,7 +23,7 @@
 	}
 	
 	public Type getType() {
-		if (symbol.getSignature().length >= 1) {
+		if (symbol.getSignature() != null && symbol.getSignature().length >= 1) {
 			return symbol.getSignature()[0];
 		}
 		return null;
diff --git a/AlgebraicDataflowArchitectureModel/src/models/algebra/Parameter.java b/AlgebraicDataflowArchitectureModel/src/models/algebra/Parameter.java
index b567ecb..ab84998 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/algebra/Parameter.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/algebra/Parameter.java
@@ -12,7 +12,8 @@
 	}
 	
 	public Parameter(String name, Type type) {
-		super(name, type);
+		super(name);
+		symbol.setSignature(new Type[] {type});
 	}
 	
 	public Parameter(Symbol symbol) {