diff --git a/Makefile.am b/Makefile.am
index 1697e2b..1243e21 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -26,8 +26,12 @@
 
 clean-local: clean-extra
 
+if IFACES_PATH
+PIMGEN_ARGS=-i $(IFACES_PATH)
+endif
+
 generated.cpp:
-	$(AM_V_GEN)$(PYTHON) $(top_srcdir)/pimgen.py -d $(extra_yamldir)/.. -o $(builddir) generate-cpp
+	$(AM_V_GEN)$(PYTHON) $(top_srcdir)/pimgen.py $(PIMGEN_ARGS) -d $(extra_yamldir)/.. -o $(builddir) generate-cpp
 
 SUBDIRS = . test
 
diff --git a/configure.ac b/configure.ac
index 526770c..83d063e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -66,10 +66,13 @@
 AC_ARG_VAR(INVENTORY_ROOT, [The DBus inventory namespace root.])
 AC_ARG_VAR(IFACE, [The manager DBus interface.])
 AC_ARG_VAR(YAML_PATH, [The path to the yaml config files.])
+AC_ARG_VAR(IFACES_PATH, [The path to the interfaces PIM can create.])
 AS_IF([test "x$BUSNAME" == "x"], [BUSNAME="xyz.openbmc_project.Inventory.Manager"])
 AS_IF([test "x$INVENTORY_ROOT" == "x"], [INVENTORY_ROOT="/xyz/openbmc_project/Inventory"])
 AS_IF([test "x$IFACE" == "x"], [IFACE="xyz.openbmc_project.Inventory.Manager"])
 AS_IF([test "x$YAML_PATH" == "x"], [YAML_PATH="$srcdir/example"])
+AM_CONDITIONAL(IFACES_PATH, [test x"$IFACES_PATH" != "x"])
+
 AC_DEFINE_UNQUOTED([BUSNAME], ["$BUSNAME"], [The DBus busname to own.])
 AC_DEFINE_UNQUOTED([INVENTORY_ROOT], ["$INVENTORY_ROOT"], [The DBus inventory namespace root.])
 AC_DEFINE_UNQUOTED([IFACE], ["$IFACE"], [The manager DBus interface.])
diff --git a/example/interfaces.d/example.yaml b/example/interfaces.d/example.yaml
deleted file mode 100644
index d5d3329..0000000
--- a/example/interfaces.d/example.yaml
+++ /dev/null
@@ -1,5 +0,0 @@
-# An interface file defines which interfaces
-# will be processed by the Notify method.
-
-- xyz.openbmc_project.Example.Iface1
-- xyz.openbmc_project.Example.Iface2
diff --git a/pimgen.py b/pimgen.py
index 0223c57..353dc15 100755
--- a/pimgen.py
+++ b/pimgen.py
@@ -468,26 +468,45 @@
                     for e in yaml.safe_load(fd.read()).get('events', {}):
                         events.append(e)
 
+        interfaces = Everything.get_interfaces(args.ifacesdir)
+        extra_interfaces = Everything.get_interfaces(
+            os.path.join(args.inputdir, 'extra_interfaces.d'))
+
         return Everything(
             *events,
-            interfaces=Everything.get_interfaces(args))
+            interfaces=interfaces + extra_interfaces)
 
     @staticmethod
-    def get_interfaces(args):
-        '''Aggregate all the interface YAML in the interfaces.d
-        directory into a single list of interfaces.'''
+    def get_interfaces(targetdir):
+        '''Scan the interfaces directory for interfaces that PIM can create.'''
 
+        yaml_files = []
         interfaces = []
-        interfaces_dir = os.path.join(args.inputdir, 'interfaces.d')
-        if os.path.exists(interfaces_dir):
-            yaml_files = filter(
-                lambda x: x.endswith('.yaml'),
-                os.listdir(interfaces_dir))
 
-            for x in yaml_files:
-                with open(os.path.join(interfaces_dir, x), 'r') as fd:
-                    for i in yaml.safe_load(fd.read()):
-                        interfaces.append(i)
+        if targetdir and os.path.exists(targetdir):
+            for directory, _, files in os.walk(targetdir):
+                if not files:
+                    continue
+
+                yaml_files += map(
+                    lambda f: os.path.relpath(
+                        os.path.join(directory, f),
+                        targetdir),
+                    filter(lambda f: f.endswith('.interface.yaml'), files))
+
+        for y in yaml_files:
+            with open(os.path.join(targetdir, y)) as fd:
+                i = y.replace('.interface.yaml', '').replace(os.sep, '.')
+
+                # PIM can't create interfaces with methods.
+                # PIM can't create interfaces without properties.
+                parsed = yaml.safe_load(fd.read())
+                if parsed.get('methods', None):
+                    continue
+                if not parsed.get('properties', None):
+                    continue
+
+                interfaces.append(i)
 
         return interfaces
 
@@ -525,6 +544,9 @@
         '-o', '--output-dir', dest='outputdir',
         default='.', help='Output directory.')
     parser.add_argument(
+        '-i', '--interfaces-dir', dest='ifacesdir',
+        help='Location of interfaces to be supported.')
+    parser.add_argument(
         '-d', '--dir', dest='inputdir',
         default=os.path.join(script_dir, 'example'),
         help='Location of files to process.')