diff --git a/schemas/material_schema.json b/schemas/material_schema.json
index 3a431823..628b2c14 100644
--- a/schemas/material_schema.json
+++ b/schemas/material_schema.json
@@ -127,6 +127,24 @@
           "type": "string",
           "description": "Relative path to a property lookup table file with electromagnetic material properties.",
           "pattern": ".*_emp\\.xompt$"
+        },
+        "retroreflectivity_data": {
+          "type": "object",
+          "description": "Information about the retro-reflective properties of the material in the visible light spectrum.",
+          "properties": {
+            "coefficient_of_retroreflection": {
+              "type": "number",
+              "description": "Coefficient of retro-reflection in cd lx^-1 m^-2."
+            },
+            "source": {
+              "type": "string",
+              "description": "Source of the retro-reflectivity data."
+            }
+          },
+          "required": [
+            "coefficient_of_retroreflection",
+            "source"
+          ]
         }
       },
       "required": [