diff --git a/nokhwa-bindings-macos/Cargo.toml b/nokhwa-bindings-macos/Cargo.toml
index fbe60a1..a5a026a 100644
--- a/nokhwa-bindings-macos/Cargo.toml
+++ b/nokhwa-bindings-macos/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "nokhwa-bindings-macos"
 version = "0.1.2"
-edition = "2021"
+edition = "2018"
 authors = ["l1npengtul"]
 license = "Apache-2.0"
 repository = "https://github.com/l1npengtul/nokhwa"
diff --git a/nokhwa-bindings-macos/src/lib.rs b/nokhwa-bindings-macos/src/lib.rs
index b2f6262..7668e6e 100644
--- a/nokhwa-bindings-macos/src/lib.rs
+++ b/nokhwa-bindings-macos/src/lib.rs
@@ -242,9 +242,9 @@ pub mod avfoundation {
     use block::ConcreteBlock;
     use cocoa_foundation::foundation::{NSArray, NSInteger, NSString, NSUInteger};
     use core_media_sys::{
-        kCMPixelFormat_422YpCbCr8_yuvs, kCMVideoCodecType_422YpCbCr8, kCMVideoCodecType_JPEG,
-        kCMVideoCodecType_JPEG_OpenDML, CMFormatDescriptionGetMediaSubType, CMSampleBufferRef,
-        CMVideoDimensions,
+        kCMPixelFormat_422YpCbCr8_yuvs, kCMPixelFormat_8IndexedGray_WhiteIsZero,
+        kCMVideoCodecType_422YpCbCr8, kCMVideoCodecType_JPEG, kCMVideoCodecType_JPEG_OpenDML,
+        CMFormatDescriptionGetMediaSubType, CMSampleBufferRef, CMVideoDimensions,
     };
     use dashmap::DashMap;
     use flume::{Receiver, Sender};
@@ -681,6 +681,7 @@ pub mod avfoundation {
     pub enum AVFourCC {
         YUV2,
         MJPEG,
+        GRAY8,
     }
 
     // Localized Name
@@ -874,6 +875,7 @@ pub mod avfoundation {
             let fourcc = match fcc_raw {
                 kCMVideoCodecType_422YpCbCr8 | kCMPixelFormat_422YpCbCr8_yuvs => AVFourCC::YUV2,
                 kCMVideoCodecType_JPEG | kCMVideoCodecType_JPEG_OpenDML => AVFourCC::MJPEG,
+                kCMPixelFormat_8IndexedGray_WhiteIsZero => AVFourCC::GRAY8,
                 _ => {
                     return Err(AVFError::InvalidValue {
                         found: fcc_raw.to_string(),
@@ -1109,7 +1111,7 @@ pub mod avfoundation {
                     Ok(avf) => avf.into_raw(),
                     Err(_) => {
                         // should not happen
-                        return Err(AVFError::StreamOpen("String contains null? This is a bug, please report it https://github.com/l1npengtul/nokhwa".to_string()));
+                        return Err(AVFError::StreamOpen("String contains null? This is a bug, please report it: https://github.com/l1npengtul/nokhwa".to_string()));
                     }
                 };
                 let queue = dispatch_queue_create(avf_queue_str, NSObject(std::ptr::null_mut()));