diff --git a/libwccl/ops/functions/bool/iteration.cpp b/libwccl/ops/functions/bool/iteration.cpp
index 86707bfc111fcc7de72d73f9c72b225af9d3151d..b900d3cb179785eb4b656a9bba955160aaf3a274 100644
--- a/libwccl/ops/functions/bool/iteration.cpp
+++ b/libwccl/ops/functions/bool/iteration.cpp
@@ -28,30 +28,34 @@ std::string Iteration::to_raw_string() const
 
 Iteration::BaseRetValPtr Iteration::apply_internal(const FunExecContext& context) const
 {
-	const boost::shared_ptr<const Position>& range_begin = left_pos_expr_->apply(context);
-	const boost::shared_ptr<const Position>& range_end = right_pos_expr_->apply(context);
-	const boost::shared_ptr<Position>& iter_var = context.variables()->get_fast(iter_var_acc_);
-
+	const boost::shared_ptr<Position>& iter_var =
+		context.variables()->get_fast(iter_var_acc_);
 	const SentenceContext& sc = context.sentence_context();
-	// Get absolute values for left and right extremes of the range
-	int left = sc.get_abs_position(*range_begin);
-	int right = sc.get_abs_position(*range_end);
 	// Proceed only if range extremes are not "nowhere".
-	if (left != Position::Nowhere && right != Position::Nowhere) {
-		// Trim range to sentence boundaries
-		if (left < 0) {
-			left = 0;
-		}
-		if (right >= sc.size()) {
-			right = sc.size() - 1;
-		}
-		// Proceed only if range isn't empty
-		if (left <= right) {
-			// Change range from absolute to relative and iterate
-			left -= sc.get_position();
-			right -= sc.get_position();
-			if (iterate(left, right, *iter_var, context)) {
-				return Predicate::True(context);
+	const boost::shared_ptr<const Position>& range_left =
+										left_pos_expr_->apply(context);
+	if (range_left->get_value() != Position::Nowhere) {
+		const boost::shared_ptr<const Position>& range_right =
+										right_pos_expr_->apply(context);
+		if (range_right->get_value() != Position::Nowhere) {
+			// Get absolute values for left and right extremes of the range.
+			int right = sc.get_abs_position(*range_end);
+			int left = sc.get_abs_position(*range_begin);
+			// Trim range to sentence boundaries
+			if (left < 0) {
+				left = 0;
+			}
+			if (right >= sc.size()) {
+				right = sc.size() - 1;
+			}
+			// Proceed only if range isn't empty
+			if (left <= right) {
+				// Change range from absolute to relative and iterate
+				left -= sc.get_position();
+				right -= sc.get_position();
+				if (iterate(left, right, *iter_var, context)) {
+					return Predicate::True(context);
+				}
 			}
 		}
 	}