diff --git a/src/libsysprof/sysprof-elf-symbol-resolver.c b/src/libsysprof/sysprof-elf-symbol-resolver.c
index 2425ed66..c81de6f1 100644
--- a/src/libsysprof/sysprof-elf-symbol-resolver.c
+++ b/src/libsysprof/sysprof-elf-symbol-resolver.c
@@ -142,34 +142,49 @@ sysprof_elf_symbol_resolver_load (SysprofSymbolResolver *resolver,
 
   while (sysprof_capture_reader_peek_type (reader, &type))
     {
-      const SysprofCaptureMap *ev;
-      SysprofMapLookaside *lookaside;
-      SysprofMap map;
+      if (type == SYSPROF_CAPTURE_FRAME_MAP)
+        {
+          const SysprofCaptureMap *ev = sysprof_capture_reader_read_map (reader);
+          SysprofMapLookaside *lookaside = g_hash_table_lookup (self->lookasides, GINT_TO_POINTER (ev->frame.pid));
+          SysprofMap map;
 
-      if (type != SYSPROF_CAPTURE_FRAME_MAP)
+          map.start = ev->start;
+          map.end = ev->end;
+          map.offset = ev->offset;
+          map.inode = ev->inode;
+          map.filename = ev->filename;
+
+          if (lookaside == NULL)
+            {
+              lookaside = sysprof_map_lookaside_new ();
+              g_hash_table_insert (self->lookasides, GINT_TO_POINTER (ev->frame.pid), lookaside);
+            }
+
+          sysprof_map_lookaside_insert (lookaside, &map);
+        }
+      else if (type == SYSPROF_CAPTURE_FRAME_PID_ROOT)
+        {
+          const SysprofCapturePidRoot *ev = sysprof_capture_reader_read_pid_root (reader);
+          SysprofMapLookaside *lookaside = g_hash_table_lookup (self->lookasides, GINT_TO_POINTER (ev->frame.pid));
+
+          if (lookaside == NULL)
+            {
+              lookaside = sysprof_map_lookaside_new ();
+              g_hash_table_insert (self->lookasides, GINT_TO_POINTER (ev->frame.pid), lookaside);
+            }
+
+          /* Someday we might need to support more layers, but currently
+           * only the base layer (0) is used.
+           */
+          if (ev->layer == 0)
+            sysprof_map_lookaside_set_root (lookaside, ev->path);
+        }
+      else
         {
           if (!sysprof_capture_reader_skip (reader))
             return;
           continue;
         }
-
-      ev = sysprof_capture_reader_read_map (reader);
-
-      map.start = ev->start;
-      map.end = ev->end;
-      map.offset = ev->offset;
-      map.inode = ev->inode;
-      map.filename = ev->filename;
-
-      lookaside = g_hash_table_lookup (self->lookasides, GINT_TO_POINTER (ev->frame.pid));
-
-      if (lookaside == NULL)
-        {
-          lookaside = sysprof_map_lookaside_new ();
-          g_hash_table_insert (self->lookasides, GINT_TO_POINTER (ev->frame.pid), lookaside);
-        }
-
-      sysprof_map_lookaside_insert (lookaside, &map);
     }
 }
 
diff --git a/src/libsysprof/sysprof-map-lookaside.c b/src/libsysprof/sysprof-map-lookaside.c
index 277e7f66..9881e4aa 100644
--- a/src/libsysprof/sysprof-map-lookaside.c
+++ b/src/libsysprof/sysprof-map-lookaside.c
@@ -24,12 +24,6 @@
 
 #include "sysprof-map-lookaside.h"
 
-struct _SysprofMapLookaside
-{
-  GSequence    *seq;
-  GStringChunk *chunk;
-};
-
 static gint
 sysprof_map_compare (gconstpointer a,
                      gconstpointer b,
@@ -107,6 +101,16 @@ sysprof_map_lookaside_insert (SysprofMapLookaside *self,
   g_sequence_insert_sorted (self->seq, copy, sysprof_map_compare, NULL);
 }
 
+void
+sysprof_map_lookaside_set_root (SysprofMapLookaside *self,
+                                const char          *root)
+{
+  g_assert (self != NULL);
+  g_assert (root != NULL);
+
+  self->root = g_string_chunk_insert_const (self->chunk, root);
+}
+
 const SysprofMap *
 sysprof_map_lookaside_lookup (SysprofMapLookaside   *self,
                               SysprofCaptureAddress  address)
diff --git a/src/libsysprof/sysprof-map-lookaside.h b/src/libsysprof/sysprof-map-lookaside.h
index ef068562..b91a03a6 100644
--- a/src/libsysprof/sysprof-map-lookaside.h
+++ b/src/libsysprof/sysprof-map-lookaside.h
@@ -26,7 +26,12 @@
 
 G_BEGIN_DECLS
 
-typedef struct _SysprofMapLookaside SysprofMapLookaside;
+typedef struct _SysprofMapLookaside
+{
+  GSequence    *seq;
+  GStringChunk *chunk;
+  const gchar  *root;
+} SysprofMapLookaside;
 
 typedef struct
 {
@@ -37,12 +42,14 @@ typedef struct
   const gchar           *filename;
 } SysprofMap;
 
-SysprofMapLookaside *sysprof_map_lookaside_new    (void);
-void                 sysprof_map_lookaside_insert (SysprofMapLookaside   *self,
-                                                   const SysprofMap      *map);
-const SysprofMap    *sysprof_map_lookaside_lookup (SysprofMapLookaside   *self,
-                                                   SysprofCaptureAddress  address);
-void                 sysprof_map_lookaside_free   (SysprofMapLookaside   *self);
+SysprofMapLookaside *sysprof_map_lookaside_new      (void);
+void                 sysprof_map_lookaside_insert   (SysprofMapLookaside    *self,
+                                                     const SysprofMap       *map);
+void                 sysprof_map_lookaside_set_root (SysprofMapLookaside    *self,
+                                                     const gchar            *root);
+const SysprofMap    *sysprof_map_lookaside_lookup   (SysprofMapLookaside    *self,
+                                                     SysprofCaptureAddress   address);
+void                 sysprof_map_lookaside_free     (SysprofMapLookaside    *self);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofMapLookaside, sysprof_map_lookaside_free)