diff --git a/Signal/src/ViewControllers/OWSTableViewController.h b/Signal/src/ViewControllers/OWSTableViewController.h
index 02c0e3a3f..8685b38ae 100644
--- a/Signal/src/ViewControllers/OWSTableViewController.h
+++ b/Signal/src/ViewControllers/OWSTableViewController.h
@@ -37,7 +37,7 @@ typedef NS_ENUM(NSInteger, OWSTableItemType) {
 };
 
 typedef void (^OWSTableActionBlock)();
-typedef UITableViewCell * (^OWSTableCustomCellBlock)();
+typedef UITableViewCell *_Nonnull (^OWSTableCustomCellBlock)();
 
 @interface OWSTableItem : NSObject
 
@@ -54,7 +54,7 @@ typedef UITableViewCell * (^OWSTableCustomCellBlock)();
 + (OWSTableItem *)itemWithCustomCellBlock:(OWSTableCustomCellBlock)customCellBlock
                               actionBlock:(nullable OWSTableActionBlock)actionBlock;
 
-- (UITableViewCell *)customCell;
+- (nullable UITableViewCell *)customCell;
 - (NSNumber *)customRowHeight;
 
 @end
diff --git a/Signal/src/ViewControllers/OWSTableViewController.m b/Signal/src/ViewControllers/OWSTableViewController.m
index c52de24e0..1d131d9e5 100644
--- a/Signal/src/ViewControllers/OWSTableViewController.m
+++ b/Signal/src/ViewControllers/OWSTableViewController.m
@@ -141,7 +141,7 @@ NS_ASSUME_NONNULL_BEGIN
     return item;
 }
 
-- (UITableViewCell *)customCell
+- (nullable UITableViewCell *)customCell
 {
     if (_customCell) {
         return _customCell;
@@ -149,7 +149,6 @@ NS_ASSUME_NONNULL_BEGIN
     if (_customCellBlock) {
         return _customCellBlock();
     }
-    OWSAssert(0);
     return nil;
 }