diff --git a/src/org/rascalmpl/library/lang/rascal/tests/functionality/Aliasing.rsc b/src/org/rascalmpl/library/lang/rascal/tests/functionality/Aliasing.rsc
index 23ce14e003b..4a7c12d69f0 100644
--- a/src/org/rascalmpl/library/lang/rascal/tests/functionality/Aliasing.rsc
+++ b/src/org/rascalmpl/library/lang/rascal/tests/functionality/Aliasing.rsc
@@ -68,6 +68,21 @@ test bool assignThroughListAlias() {
   values[0] = 3;
   return values == [3, 2];
 }
+
+alias Pair[&T] = tuple[&T first, int second];
+
+test bool assignFieldThroughParameterizedTupleAlias() {
+  Pair[str] p = <"a", 1>;
+  p.second = 2;
+  return p == <"a", 2>;
+}
+
+Pair[&T] incSecond(Pair[&T] p) {
+  p.second += 1;
+  return p;
+}
+
+test bool assignFieldThroughGenericTupleAlias() = incSecond(<"a", 1>) == <"a", 2>;
 		  
 alias trans = tuple[str, str, str]; 
 alias block = set[trans];
diff --git a/src/org/rascalmpl/semantics/dynamic/Assignable.java b/src/org/rascalmpl/semantics/dynamic/Assignable.java
index 0687edb3896..09546790c10 100644
--- a/src/org/rascalmpl/semantics/dynamic/Assignable.java
+++ b/src/org/rascalmpl/semantics/dynamic/Assignable.java
@@ -239,9 +239,9 @@ public Result<IValue> assignment(AssignableEvaluator __eval) {
 				throw new UninitializedVariable(label, this.getReceiver());
 			}
 
-			if (receiver.getStaticType().isTuple()) {
+			if (receiver.getStaticUnaliasedType().isTuple()) {
 
-				int idx = receiver.getStaticType().getFieldIndex(label);
+				int idx = receiver.getStaticUnaliasedType().getFieldIndex(label);
 				if (idx < 0) {
 					throw new UndeclaredField(label, receiver.getStaticType(), this);
 				}