diff --git a/src/blenderbim/blenderbim/bim/module/tester/operator.py b/src/blenderbim/blenderbim/bim/module/tester/operator.py
index 8560462eb2..dcc1165068 100644
--- a/src/blenderbim/blenderbim/bim/module/tester/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/tester/operator.py
@@ -27,6 +27,7 @@ import ifctester.reporter
 import ifcopenshell
 import blenderbim.tool as tool
 import blenderbim.bim.handler
+from blenderbim.bim.operator import MultipleFileSelector
 from pathlib import Path
 
 
@@ -92,38 +93,32 @@ class ExecuteIfcTester(bpy.types.Operator, tool.Ifc.Operator):
         return {"FINISHED"}
 
 
-class SelectSpecs(bpy.types.Operator):
+class SelectSpecs(MultipleFileSelector):
     bl_idname = "bim.select_specs"
     bl_label = "Select IDS"
-    bl_options = {"REGISTER", "UNDO"}
     filename_ext = ".ids"
     filter_glob: bpy.props.StringProperty(default="*.ids;*.xml", options={"HIDDEN"})
     filepath: bpy.props.StringProperty(subtype="FILE_PATH")
 
     def execute(self, context):
-        context.scene.IfcTesterProperties.specs = self.filepath
+        props = context.scene.IfcTesterProperties
+
+        self.update_props(props, "specs", props.specs_files)
         return {"FINISHED"}
 
-    def invoke(self, context, event):
-        context.window_manager.fileselect_add(self)
-        return {"RUNNING_MODAL"}
 
 
-class SelectIfcTesterIfcFile(bpy.types.Operator):
+class SelectIfcTesterIfcFile(MultipleFileSelector):
     bl_idname = "bim.select_ifctester_ifc_file"
     bl_label = "Select IfcTester IFC File"
-    bl_options = {"REGISTER", "UNDO"}
     filename_ext = ".ifc"
     filter_glob: bpy.props.StringProperty(default="*.ifc;*.ifczip;*.ifcxml", options={"HIDDEN"})
-    filepath: bpy.props.StringProperty(subtype="FILE_PATH")
 
     def execute(self, context):
-        context.scene.IfcTesterProperties.ifc_file = self.filepath
-        return {"FINISHED"}
+        props = context.scene.IfcTesterProperties
 
-    def invoke(self, context, event):
-        context.window_manager.fileselect_add(self)
-        return {"RUNNING_MODAL"}
+        self.update_props(props, "ifc_file", props.ifc_files)
+        return {"FINISHED"}
 
 
 class SelectRequirement(bpy.types.Operator):
diff --git a/src/blenderbim/blenderbim/bim/module/tester/prop.py b/src/blenderbim/blenderbim/bim/module/tester/prop.py
index 96e5a939f9..9e4dbb88e1 100644
--- a/src/blenderbim/blenderbim/bim/module/tester/prop.py
+++ b/src/blenderbim/blenderbim/bim/module/tester/prop.py
@@ -49,7 +49,9 @@ class FailedEntities(PropertyGroup):
 
 class IfcTesterProperties(PropertyGroup):
     specs: StringProperty(default="", name="IDS File")
+    specs_files: CollectionProperty(name="IDS Files", type=StrProperty)
     ifc_file: StringProperty(default="", name="IFC File")
+    ifc_files: CollectionProperty(name="IFC Files", type=StrProperty)
     should_load_from_memory: BoolProperty(default=False, name="Load from Memory")
     generate_html_report: BoolProperty(default=False, name="Generate HTML report", options=set())
     generate_ods_report: BoolProperty(default=False, name="Generate ODS report", options=set())
diff --git a/src/blenderbim/blenderbim/bim/module/tester/ui.py b/src/blenderbim/blenderbim/bim/module/tester/ui.py
index b4ae0bcdad..e864580691 100644
--- a/src/blenderbim/blenderbim/bim/module/tester/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/tester/ui.py
@@ -50,11 +50,18 @@ class BIM_PT_tester(Panel):
 
         if not tool.Ifc.get() or not props.should_load_from_memory:
             row = self.layout.row(align=True)
-            row.prop(props, "ifc_file")
+            if len(props.ifc_files) > 1:
+                row.label(text=f"{len(props.ifc_files)} Files Selected")
+            else:
+                row.prop(props, "ifc_file")
+
             row.operator("bim.select_ifctester_ifc_file", icon="FILE_FOLDER", text="")
 
         row = self.layout.row(align=True)
-        row.prop(props, "specs")
+        if len(props.specs_files) > 1:
+            row.label(text=f"{len(props.specs_files)} Files Selected")
+        else:
+            row.prop(props, "specs")
         row.operator("bim.select_specs", icon="FILE_FOLDER", text="")
 
         row = self.layout.row()