diff --git a/src/qir/ast/data/QIRLcons.java b/src/qir/ast/data/QIRLcons.java
index 61755dc018cdd1054dbb53ca72d87c0a4b455244..21df24511fed3afab936f76d51c8a414832ff6fa 100644
--- a/src/qir/ast/data/QIRLcons.java
+++ b/src/qir/ast/data/QIRLcons.java
@@ -36,7 +36,7 @@ public final class QIRLcons extends QIRList {
 
     @Override
     public final String toString() {
-        return "[ " + value + ", " + tail + "]" + (type == null ? "" : " : " + type);
+        return "[ " + value + ", " + tail + "]" + (type.isPresent() ? " : " + type : "");
     }
 
     @Override
diff --git a/src/qir/ast/data/QIRRcons.java b/src/qir/ast/data/QIRRcons.java
index c01acf6862f16e24f4bc40b9ebbe2c7aa5c46152..e4bc0e869e81a86fa68d5da11e37d9208567a8ee 100644
--- a/src/qir/ast/data/QIRRcons.java
+++ b/src/qir/ast/data/QIRRcons.java
@@ -45,7 +45,7 @@ public final class QIRRcons extends QIRRecord {
 
     @Override
     public final String toString() {
-        return "{ " + id + ":" + value + "; " + tail + "}" + (type == null ? "" : " : " + type);
+        return "{ " + id + ":" + value + "; " + tail + "}" + (type.isPresent() ? " : " + type : "");
     }
 
     @Override