4 files changed, 7 insertions, 7 deletions
diff --git a/src/libcola/cola.h b/src/libcola/cola.h
index b56d2327e..eda64cb5f 100644
--- a/src/libcola/cola.h
+++ b/src/libcola/cola.h
@@ -28,7 +28,7 @@ namespace cola {
         vector<Rectangle*> rects;
         vector<Edge> edges;
         SimpleConstraints scx, scy;
-        ~Component();
+        virtual ~Component();
         void moveRectangles(double x, double y);
         Rectangle* getBoundingBox();
     };
@@ -174,7 +174,7 @@ namespace cola {
 
         void setupDummyVars();
 
-        ~ConstrainedMajorizationLayout() {
+        virtual ~ConstrainedMajorizationLayout() {
             if(boundingBoxes) {
                 delete [] boundingBoxes;
             }
diff --git a/src/libcola/cycle_detector.h b/src/libcola/cycle_detector.h
index fcb8722fe..18286ac50 100644
--- a/src/libcola/cycle_detector.h
+++ b/src/libcola/cycle_detector.h
@@ -21,13 +21,13 @@ class Node  {
     StatusType status;
 
     Node(unsigned id)  { this->id = id; cyclicAncestor = NULL; status = NotVisited; }
-    ~Node()  {}
+    virtual ~Node()  {}
 };
 
 class CycleDetector  {
   public:
     CycleDetector(unsigned numVertices, Edges *edges);
-    ~CycleDetector();
+    virtual ~CycleDetector();
     std::vector<bool> *detect_cycles();
     void mod_graph(unsigned numVertices, Edges *edges);
     unsigned getV()  { return this->V; }
diff --git a/src/libcola/gradient_projection.h b/src/libcola/gradient_projection.h
index 9ee3ff5c5..4ef68fc2e 100644
--- a/src/libcola/gradient_projection.h
+++ b/src/libcola/gradient_projection.h
@@ -223,7 +223,7 @@ public:
             constrained=true;
         }
 	}
-    ~GradientProjection() {
+    virtual ~GradientProjection() {
         delete [] g;
         delete [] d;
         delete [] old_place;
diff --git a/src/libcola/straightener.h b/src/libcola/straightener.h
index e2c50a3a6..934be45ba 100644
--- a/src/libcola/straightener.h
+++ b/src/libcola/straightener.h
@@ -10,7 +10,7 @@
 namespace straightener {
     struct Route {
         Route(unsigned n) : n(n), xs(new double[n]), ys(new double[n]) {}
-        ~Route() {
+        virtual ~Route() {
             delete [] xs;
             delete [] ys;
         }
@@ -42,7 +42,7 @@ namespace straightener {
         {
             route->boundingBox(xmin,ymin,xmax,ymax);
         }
-        ~Edge() {
+        virtual ~Edge() {
             delete route;
         }
         void setRoute(Route* r) {