diff --git a/rigify/utils/rig.py b/rigify/utils/rig.py
index 71201eab1..010c88f71 100644
--- a/rigify/utils/rig.py
+++ b/rigify/utils/rig.py
@@ -295,6 +295,7 @@ def write_metarig(obj: ArmatureObject, layers=False, func_name="create",
     """
     code = [
         "import bpy\n",
+        "from rna_prop_ui import rna_idprop_ui_create\n",
         "from mathutils import Color\n\n",
     ]
 
@@ -412,6 +413,42 @@ def write_metarig(obj: ArmatureObject, layers=False, func_name="create",
                 code.append("    except AttributeError:")
                 code.append("        pass")
 
+        # Custom properties
+        custom_properties = {
+            property_name: value for property_name, value in pbone.items()
+            if property_name not in pbone.bl_rna.properties.keys()
+            and type(pbone[property_name]) in (float, int)
+        }
+
+        if custom_properties:
+            code.append('    # custom properties')
+
+        for custom_property, current_value in custom_properties.items():
+            props_data = pbone.id_properties_ui(custom_property).as_dict()
+            code.append(f"    rna_idprop_ui_create(")
+            code.append(f"        pbone,")
+            code.append(f"        {custom_property!r},")
+            code.append(f"        default={props_data['default']!r},")
+            if 'min' in props_data:
+                code.append(f"        min={props_data['min']},")
+            if 'max' in props_data:
+                code.append(f"        max={props_data['max']},")
+            if 'soft_min' in props_data:
+                code.append(f"        soft_min={props_data['soft_min']},")
+            if 'soft_max' in props_data:
+                code.append(f"        soft_max={props_data['soft_max']},")
+            if 'subtype' in props_data:
+                code.append(f"        subtype={props_data['subtype']!r},")
+            if 'description' in props_data:
+                code.append(f"        description={props_data['description']!r},")
+            if 'precision' in props_data:
+                code.append(f"        precision={props_data['precision']},")
+            if 'step' in props_data:
+                code.append(f"        step={props_data['step']},")
+            code.append(f"    )")
+            if props_data['default'] != current_value:
+                code.append(f"    pbone[{custom_property!r}] = {current_value}")
+
         # Constraints
         for con in pbone.constraints:
             code.append("    con = pbone.constraints.new(%r)" % con.type)