diff --git a/tools/unity-avatar-exporter/Assets/Editor/AvatarExporter/AvatarExporter.cs b/tools/unity-avatar-exporter/Assets/Editor/AvatarExporter/AvatarExporter.cs
index 142e4ae35a..f0d970031c 100644
--- a/tools/unity-avatar-exporter/Assets/Editor/AvatarExporter/AvatarExporter.cs
+++ b/tools/unity-avatar-exporter/Assets/Editor/AvatarExporter/AvatarExporter.cs
@@ -1105,6 +1105,11 @@ class AvatarExporter : MonoBehaviour {
             string materialName = material.name;
             string shaderName = material.shader.name;
             
+            // if this material isn't mapped externally then ignore it
+            if (!materialMappings.ContainsValue(materialName)) {
+                continue;
+            }
+            
             // don't store any material data for unsupported shader types
             if (Array.IndexOf(SUPPORTED_SHADERS, shaderName) == -1) {
                 if (!unsupportedShaderMaterials.Contains(materialName)) {
diff --git a/tools/unity-avatar-exporter/avatarExporter.unitypackage b/tools/unity-avatar-exporter/avatarExporter.unitypackage
index ee3f6abe01..48a9502079 100644
Binary files a/tools/unity-avatar-exporter/avatarExporter.unitypackage and b/tools/unity-avatar-exporter/avatarExporter.unitypackage differ