diff --git a/src/main/java/pythagoras/d/AbstractLine.java b/src/main/java/pythagoras/d/AbstractLine.java
index 38e31b3..a5bb27a 100644
--- a/src/main/java/pythagoras/d/AbstractLine.java
+++ b/src/main/java/pythagoras/d/AbstractLine.java
@@ -89,7 +89,7 @@ public abstract class AbstractLine implements ILine
 
     @Override // from interface IShape
     public boolean isEmpty () {
-        return false;
+        return true;
     }
 
     @Override // from interface IShape
diff --git a/src/main/java/pythagoras/f/AbstractLine.java b/src/main/java/pythagoras/f/AbstractLine.java
index 4720615..ec4ba48 100644
--- a/src/main/java/pythagoras/f/AbstractLine.java
+++ b/src/main/java/pythagoras/f/AbstractLine.java
@@ -89,7 +89,7 @@ public abstract class AbstractLine implements ILine
 
     @Override // from interface IShape
     public boolean isEmpty () {
-        return false;
+        return true;
     }
 
     @Override // from interface IShape