diff --git a/org.eclipse.equinox.p2.cudf/src/main/java/org/eclipse/equinox/p2/cudf/solver/Projector.java b/org.eclipse.equinox.p2.cudf/src/main/java/org/eclipse/equinox/p2/cudf/solver/Projector.java
index c87facc..5bcda20 100644
--- a/org.eclipse.equinox.p2.cudf/src/main/java/org/eclipse/equinox/p2/cudf/solver/Projector.java
+++ b/org.eclipse.equinox.p2.cudf/src/main/java/org/eclipse/equinox/p2/cudf/solver/Projector.java
@@ -502,7 +502,8 @@
 	}
 
 	public void stopSolver() {
-		dependencyHelper.stopSolver();
+		if (dependencyHelper != null)
+			dependencyHelper.stopSolver();
 	}
 
 	public Collection getBestSolutionFoundSoFar() {