diff --git a/src/libsysprof-analyze/sysprof-document-counter.c b/src/libsysprof-analyze/sysprof-document-counter.c
index 8a810295..7f857521 100644
--- a/src/libsysprof-analyze/sysprof-document-counter.c
+++ b/src/libsysprof-analyze/sysprof-document-counter.c
@@ -44,6 +44,7 @@ enum {
   PROP_CATEGORY,
   PROP_DESCRIPTION,
   PROP_ID,
+  PROP_KEY,
   PROP_MAX_VALUE,
   PROP_MIN_VALUE,
   PROP_NAME,
@@ -133,6 +134,10 @@ sysprof_document_counter_get_property (GObject    *object,
       g_value_set_string (value, sysprof_document_counter_get_name (self));
       break;
 
+    case PROP_KEY:
+      g_value_take_string (value, sysprof_document_counter_dup_key (self));
+      break;
+
     case PROP_ID:
       g_value_set_uint (value, sysprof_document_counter_get_id (self));
       break;
@@ -165,6 +170,11 @@ sysprof_document_counter_class_init (SysprofDocumentCounterClass *klass)
                          NULL,
                          (G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
 
+  properties [PROP_KEY] =
+    g_param_spec_string ("key", NULL, NULL,
+                         NULL,
+                         (G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
   properties [PROP_NAME] =
     g_param_spec_string ("name", NULL, NULL,
                          NULL,
@@ -400,3 +410,11 @@ sysprof_document_counter_get_min_value (SysprofDocumentCounter *self)
 
   return self->min_value;
 }
+
+char *
+sysprof_document_counter_dup_key (SysprofDocumentCounter *self)
+{
+  g_return_val_if_fail (SYSPROF_IS_DOCUMENT_COUNTER (self), NULL);
+
+  return g_strdup_printf ("%s/%s", self->category, self->name);
+}
diff --git a/src/libsysprof-analyze/sysprof-document-counter.h b/src/libsysprof-analyze/sysprof-document-counter.h
index 1fbfe071..fec9b3ac 100644
--- a/src/libsysprof-analyze/sysprof-document-counter.h
+++ b/src/libsysprof-analyze/sysprof-document-counter.h
@@ -31,6 +31,8 @@ G_BEGIN_DECLS
 SYSPROF_AVAILABLE_IN_ALL
 G_DECLARE_FINAL_TYPE (SysprofDocumentCounter, sysprof_document_counter, SYSPROF, DOCUMENT_COUNTER, GObject)
 
+SYSPROF_AVAILABLE_IN_ALL
+char       *sysprof_document_counter_dup_key          (SysprofDocumentCounter *self);
 SYSPROF_AVAILABLE_IN_ALL
 const char *sysprof_document_counter_get_category     (SysprofDocumentCounter *self);
 SYSPROF_AVAILABLE_IN_ALL