diff --git a/src/main/wacc/typeChecker.scala b/src/main/wacc/typeChecker.scala
index 38b34e3..f0f523b 100644
--- a/src/main/wacc/typeChecker.scala
+++ b/src/main/wacc/typeChecker.scala
@@ -159,7 +159,7 @@ object typeChecker {
       ctx.typeOf(id).satisfies(constraint, id.pos)
     case ArrayElem(id, indices) =>
       val arrayTy = ctx.typeOf(id)
-      val elemTy = indices.toList.foldRight(arrayTy) { (elem, acc) =>
+      val elemTy = indices.foldLeft(arrayTy) { (acc, elem) =>
         checkValue(elem, Constraint.Is(KnownType.Int, "array index must be an int"))
         acc match {
           case KnownType.Array(innerTy) => innerTy
@@ -173,10 +173,10 @@ object typeChecker {
     case Parens(expr) => checkValue(expr, constraint)
     case l @ ArrayLiter(elems) =>
       KnownType
-        .Array(elems.foldRight[SemType](?) { case (elem, acc) =>
+        .Array(elems.foldLeft[SemType](?) { case (acc, elem) =>
           checkValue(
             elem,
-            Constraint.IsSymmetricCompatible(acc, "array elements must have the same type")
+            Constraint.IsSymmetricCompatible(acc, s"array elements must have the same type")
           )
         })
         .satisfies(constraint, l.pos)