diff --git a/src/main/java/org/klomp/cassowary/clconstraint/ClLinearConstraint.java b/src/main/java/org/klomp/cassowary/clconstraint/ClLinearConstraint.java
index 4f0e426..88dc30f 100644
--- a/src/main/java/org/klomp/cassowary/clconstraint/ClLinearConstraint.java
+++ b/src/main/java/org/klomp/cassowary/clconstraint/ClLinearConstraint.java
@@ -17,7 +17,7 @@
 import org.klomp.cassowary.ClLinearExpression;
 import org.klomp.cassowary.ClStrength;
 
-class ClLinearConstraint extends ClConstraint {
+public abstract class ClLinearConstraint extends ClConstraint {
     protected ClLinearExpression _expression;
 
     public ClLinearConstraint(ClLinearExpression cle, ClStrength strength, double weight) {