diff --git a/src/libsysprof-analyze/sysprof-callgraph.c b/src/libsysprof-analyze/sysprof-callgraph.c
index db46db92..caf0f08f 100644
--- a/src/libsysprof-analyze/sysprof-callgraph.c
+++ b/src/libsysprof-analyze/sysprof-callgraph.c
@@ -329,6 +329,7 @@ sysprof_callgraph_add_traceable (SysprofCallgraph         *self,
     self->augment_func (self,
                         node,
                         SYSPROF_DOCUMENT_FRAME (traceable),
+                        TRUE,
                         self->augment_func_data);
 }
 
diff --git a/src/libsysprof-analyze/sysprof-callgraph.h b/src/libsysprof-analyze/sysprof-callgraph.h
index 5e5e0cb0..e5057687 100644
--- a/src/libsysprof-analyze/sysprof-callgraph.h
+++ b/src/libsysprof-analyze/sysprof-callgraph.h
@@ -42,6 +42,7 @@ typedef struct _SysprofCallgraphNode SysprofCallgraphNode;
  * @callgraph: the callgraph being augmented
  * @node: the node within the callgraph
  * @frame: the frame used to generate this node
+ * @summarize: if summaries should be generated
  * @user_data: closure data for augmentation func
  *
  * This function is called for the bottom most node in a trace as it is added
@@ -50,11 +51,15 @@ typedef struct _SysprofCallgraphNode SysprofCallgraphNode;
  * The augmentation func should augment the node in whatever way it sees fit
  * and generally will want to walk up the node tree to the root to augment the
  * parents as it goes. Your augmentation function is not called for each node,
- * only the last node.
+ * only the deepest node.
+ *
+ * If @summarize is %TRUE, then you should also generate summary augmentation
+ * using sysprof_callgraph_get_summary_augment() or similar.
  */
 typedef void (*SysprofAugmentationFunc) (SysprofCallgraph     *callgraph,
                                          SysprofCallgraphNode *node,
                                          SysprofDocumentFrame *frame,
+                                         gboolean              summarize,
                                          gpointer              user_data);
 
 SYSPROF_AVAILABLE_IN_ALL
diff --git a/src/libsysprof-analyze/sysprof-descendants-model.c b/src/libsysprof-analyze/sysprof-descendants-model.c
index ac99cdc3..025a2ed3 100644
--- a/src/libsysprof-analyze/sysprof-descendants-model.c
+++ b/src/libsysprof-analyze/sysprof-descendants-model.c
@@ -192,12 +192,11 @@ sysprof_descendants_model_add_traceable (SysprofDescendantsModel  *self,
 
       node = sysprof_descendants_model_add_trace (self, symbols, n_symbols);
 
-      /* TODO: This will fuck up summaries */
-
       if (node && self->callgraph->augment_func)
         self->callgraph->augment_func (self->callgraph,
                                        node,
                                        SYSPROF_DOCUMENT_FRAME (traceable),
+                                       FALSE,
                                        self->callgraph->augment_func_data);
     }
 }
diff --git a/src/libsysprof-analyze/tests/test-callgraph.c b/src/libsysprof-analyze/tests/test-callgraph.c
index 03479b2c..49ca0bea 100644
--- a/src/libsysprof-analyze/tests/test-callgraph.c
+++ b/src/libsysprof-analyze/tests/test-callgraph.c
@@ -91,6 +91,7 @@ static void
 augment_cb (SysprofCallgraph     *callgraph,
             SysprofCallgraphNode *node,
             SysprofDocumentFrame *frame,
+            gboolean              summarize,
             gpointer              user_data)
 {
   Augment *aug;
diff --git a/src/libsysprof-gtk/sysprof-callgraph-view-private.h b/src/libsysprof-gtk/sysprof-callgraph-view-private.h
index 934cea32..f574bd74 100644
--- a/src/libsysprof-gtk/sysprof-callgraph-view-private.h
+++ b/src/libsysprof-gtk/sysprof-callgraph-view-private.h
@@ -54,10 +54,7 @@ struct _SysprofCallgraphViewClass
   GtkWidgetClass parent_class;
 
   gsize augment_size;
-  void (*augment_func) (SysprofCallgraph     *callgraph,
-                        SysprofCallgraphNode *node,
-                        SysprofDocumentFrame *frame,
-                        gpointer              user_data);
+  SysprofAugmentationFunc augment_func;
 
   void (*load) (SysprofCallgraphView *self,
                 SysprofCallgraph     *callgraph);
diff --git a/src/libsysprof-gtk/sysprof-weighted-callgraph-view.c b/src/libsysprof-gtk/sysprof-weighted-callgraph-view.c
index e1cfa7e6..f1ac08da 100644
--- a/src/libsysprof-gtk/sysprof-weighted-callgraph-view.c
+++ b/src/libsysprof-gtk/sysprof-weighted-callgraph-view.c
@@ -61,6 +61,7 @@ static void
 augment_weight (SysprofCallgraph     *callgraph,
                 SysprofCallgraphNode *node,
                 SysprofDocumentFrame *frame,
+                gboolean              summarize,
                 gpointer              user_data)
 {
   AugmentWeight *cur;
@@ -75,9 +76,12 @@ augment_weight (SysprofCallgraph     *callgraph,
   cur->size += 1;
   cur->total += 1;
 
-  sum = sysprof_callgraph_get_summary_augment (callgraph, node);
-  sum->size += 1;
-  sum->total += 1;
+  if (summarize)
+    {
+      sum = sysprof_callgraph_get_summary_augment (callgraph, node);
+      sum->size += 1;
+      sum->total += 1;
+    }
 
   for (node = sysprof_callgraph_node_parent (node);
        node != NULL;
@@ -86,8 +90,11 @@ augment_weight (SysprofCallgraph     *callgraph,
       cur = sysprof_callgraph_get_augment (callgraph, node);
       cur->total += 1;
 
-      sum = sysprof_callgraph_get_summary_augment (callgraph, node);
-      sum->total += 1;
+      if (summarize)
+        {
+          sum = sysprof_callgraph_get_summary_augment (callgraph, node);
+          sum->total += 1;
+        }
     }
 }