diff --git a/src/libsysprof/sysprof-document-bitset-index-private.h b/src/libsysprof/sysprof-document-bitset-index-private.h
index 0432f441..53913d67 100644
--- a/src/libsysprof/sysprof-document-bitset-index-private.h
+++ b/src/libsysprof/sysprof-document-bitset-index-private.h
@@ -29,7 +29,10 @@ G_BEGIN_DECLS
 
 G_DECLARE_FINAL_TYPE (SysprofDocumentBitsetIndex, sysprof_document_bitset_index, SYSPROF, DOCUMENT_BITSET_INDEX, GObject)
 
-GListModel *_sysprof_document_bitset_index_new (GListModel *model,
-                                                EggBitset  *bitset);
+GListModel *_sysprof_document_bitset_index_new      (GListModel *model,
+                                                     EggBitset  *bitset);
+GListModel *_sysprof_document_bitset_index_new_full (GListModel *model,
+                                                     EggBitset  *bitset,
+                                                     GType       type);
 
 G_END_DECLS
diff --git a/src/libsysprof/sysprof-document-bitset-index.c b/src/libsysprof/sysprof-document-bitset-index.c
index 112cb6e6..d311dc9f 100644
--- a/src/libsysprof/sysprof-document-bitset-index.c
+++ b/src/libsysprof/sysprof-document-bitset-index.c
@@ -27,6 +27,7 @@ struct _SysprofDocumentBitsetIndex
   GObject parent_instance;
   GListModel *model;
   EggBitset *bitset;
+  GType type;
 };
 
 static GType
@@ -34,6 +35,9 @@ sysprof_document_bitset_index_get_item_type (GListModel *model)
 {
   SysprofDocumentBitsetIndex *self = SYSPROF_DOCUMENT_BITSET_INDEX (model);
 
+  if (self->type)
+    return self->type;
+
   if (self->model != NULL)
     return g_list_model_get_item_type (self->model);
 
@@ -138,8 +142,9 @@ sysprof_document_bitset_index_init (SysprofDocumentBitsetIndex *self)
 }
 
 GListModel *
-_sysprof_document_bitset_index_new (GListModel *model,
-                                    EggBitset  *bitset)
+_sysprof_document_bitset_index_new_full (GListModel *model,
+                                         EggBitset  *bitset,
+                                         GType       type)
 {
   SysprofDocumentBitsetIndex *self;
 
@@ -149,6 +154,14 @@ _sysprof_document_bitset_index_new (GListModel *model,
   self = g_object_new (SYSPROF_TYPE_DOCUMENT_BITSET_INDEX, NULL);
   self->model = g_object_ref (model);
   self->bitset = egg_bitset_ref (bitset);
+  self->type = type;
 
   return G_LIST_MODEL (self);
 }
+
+GListModel *
+_sysprof_document_bitset_index_new (GListModel *model,
+                                    EggBitset  *bitset)
+{
+  return _sysprof_document_bitset_index_new_full (model, bitset, G_TYPE_INVALID);
+}
diff --git a/src/libsysprof/sysprof-document.c b/src/libsysprof/sysprof-document.c
index c92e6090..e48fe125 100644
--- a/src/libsysprof/sysprof-document.c
+++ b/src/libsysprof/sysprof-document.c
@@ -32,6 +32,7 @@
 #include "sysprof-bundled-symbolizer-private.h"
 #include "sysprof-callgraph-private.h"
 #include "sysprof-cpu-info-private.h"
+#include "sysprof-document-allocation.h"
 #include "sysprof-document-bitset-index-private.h"
 #include "sysprof-document-counter-private.h"
 #include "sysprof-document-ctrdef.h"
@@ -43,6 +44,7 @@
 #include "sysprof-document-mmap.h"
 #include "sysprof-document-overlay.h"
 #include "sysprof-document-process-private.h"
+#include "sysprof-document-sample.h"
 #include "sysprof-document-symbols-private.h"
 #include "sysprof-mark-catalog-private.h"
 #include "sysprof-mount-private.h"
@@ -1789,7 +1791,7 @@ sysprof_document_list_allocations (SysprofDocument *self)
 {
   g_return_val_if_fail (SYSPROF_IS_DOCUMENT (self), NULL);
 
-  return _sysprof_document_bitset_index_new (G_LIST_MODEL (self), self->allocations);
+  return _sysprof_document_bitset_index_new_full (G_LIST_MODEL (self), self->allocations, SYSPROF_TYPE_DOCUMENT_ALLOCATION);
 }
 
 /**
@@ -1806,7 +1808,7 @@ sysprof_document_list_samples (SysprofDocument *self)
 {
   g_return_val_if_fail (SYSPROF_IS_DOCUMENT (self), NULL);
 
-  return _sysprof_document_bitset_index_new (G_LIST_MODEL (self), self->samples);
+  return _sysprof_document_bitset_index_new_full (G_LIST_MODEL (self), self->samples, SYSPROF_TYPE_DOCUMENT_SAMPLE);
 }
 
 /**
@@ -1823,7 +1825,7 @@ sysprof_document_list_samples_with_context_switch (SysprofDocument *self)
 {
   g_return_val_if_fail (SYSPROF_IS_DOCUMENT (self), NULL);
 
-  return _sysprof_document_bitset_index_new (G_LIST_MODEL (self), self->samples_with_context_switch);
+  return _sysprof_document_bitset_index_new_full (G_LIST_MODEL (self), self->samples_with_context_switch, SYSPROF_TYPE_DOCUMENT_SAMPLE);
 }
 
 /**
@@ -1845,7 +1847,7 @@ sysprof_document_list_samples_without_context_switch (SysprofDocument *self)
   bitset = egg_bitset_copy (self->samples);
   egg_bitset_subtract (bitset, self->samples_with_context_switch);
 
-  return _sysprof_document_bitset_index_new (G_LIST_MODEL (self), bitset);
+  return _sysprof_document_bitset_index_new_full (G_LIST_MODEL (self), bitset, SYSPROF_TYPE_DOCUMENT_SAMPLE);
 }
 
 /**