diff --git a/CHANGELOG.md b/CHANGELOG.md
index fa16b5fe..7ae471c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -94,6 +94,8 @@ The changelog for `IGListKit`. Also see the [releases](https://github.com/instag
 
 ### Fixes
 
+- Don't crash if you use `IGListSectionController` without a subclass [Maxime Ollivier](https://github.com/maxolls) (tbd)
+
 - Testing crash fix when calling `-[IGListAdapter reloadObjects ...]` during an update [Maxime Ollivier](https://github.com/maxolls) (tbd)
 
 - Repaired Swift Package Manager support. [Petro Rovenskyy](https://github.com/3a4oT/) [(#1487)](https://github.com/Instagram/IGListKit/pull/1487)
diff --git a/Source/IGListKit/IGListAdapter.m b/Source/IGListKit/IGListAdapter.m
index 72db9d0d..21e79524 100644
--- a/Source/IGListKit/IGListAdapter.m
+++ b/Source/IGListKit/IGListAdapter.m
@@ -709,6 +709,15 @@ typedef struct OffsetRange {
                     dataSource, object);
             return;
         }
+        
+        if ([sectionController isMemberOfClass:[IGListSectionController class]]) {
+            // If IGListSectionController is not subclassed, it could be a side effect of a problem. For example, nothing stops
+            // dataSource from returning a plain IGListSectionController if it doesn't recognize the object type, instead of throwing.
+            // Why not throw here then? Maybe we should, but in most cases, it feels like an over reaction. If we don't know how to render
+            // a single item, terminating the entire app might not be necessary. The dataSource should be the one who decides if throwing is appropriate.
+            IGFailAssert(@"Ignoring IGListSectionController that's not a subclass from data source %@ for object %@", NSStringFromClass([dataSource class]), NSStringFromClass([object class]));
+            return;
+        }
 
         // in case the section controller was created outside of -listAdapter:sectionControllerForObject:
         sectionController.collectionContext = self;
diff --git a/Tests/IGListAdapterE2ETests.m b/Tests/IGListAdapterE2ETests.m
index e5979d50..afe2ca00 100644
--- a/Tests/IGListAdapterE2ETests.m
+++ b/Tests/IGListAdapterE2ETests.m
@@ -16,6 +16,7 @@
 #import "IGListAdapterUpdater.h"
 #import "IGListAdapterUpdaterInternal.h"
 #import "IGListTestCase.h"
+#import "IGListTestCollectionViewLayout.h"
 #import "IGListTestHelpers.h"
 #import "IGListTestOffsettingLayout.h"
 #import "IGListUpdateTransactionBuilder.h"
@@ -2643,4 +2644,20 @@
     [self waitForExpectationsWithTimeout:30 handler:nil];
 }
 
+- (void)test_whenSectionControllerNotSubclassed_thatDoesNotCrash {
+    // We need a custom layout that creates attributes for all cells, even the ones with size
+    // zero, so that the UICollectionView requests all cells. Using `UICollectionViewDelegateFlowLayout`
+    // doesn't crash, because it doesn't seem to return attributes where the size is zero.
+    self.collectionView.collectionViewLayout = [IGListTestCollectionViewLayout new];
+
+    [self setupWithObjects:@[kIGTestDelegateDataSourceNoSectionControllerSubclass]];
+
+    XCTestExpectation *expectation = genExpectation;
+    [self.adapter reloadDataWithCompletion:^(BOOL finished) {
+        [self.collectionView layoutIfNeeded];
+        [expectation fulfill];
+    }];
+    [self waitForExpectationsWithTimeout:30 handler:nil];
+}
+
 @end
diff --git a/Tests/Objects/IGListTestCollectionViewLayout.h b/Tests/Objects/IGListTestCollectionViewLayout.h
new file mode 100644
index 00000000..28c9c8f0
--- /dev/null
+++ b/Tests/Objects/IGListTestCollectionViewLayout.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/// Layout that 1) creates all attributes regardless of size, and 2) positions them with origin (0,0)
+@interface IGListTestCollectionViewLayout : UICollectionViewLayout
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Tests/Objects/IGListTestCollectionViewLayout.m b/Tests/Objects/IGListTestCollectionViewLayout.m
new file mode 100644
index 00000000..f4c3934c
--- /dev/null
+++ b/Tests/Objects/IGListTestCollectionViewLayout.m
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "IGListTestCollectionViewLayout.h"
+
+@implementation IGListTestCollectionViewLayout {
+    NSDictionary<NSIndexPath *, UICollectionViewLayoutAttributes *> *_attributes;
+}
+
+- (void)prepareLayout {
+    UICollectionView *const collectionView = self.collectionView;
+    
+    // Get the UICollectionViewDelegateFlowLayout for sizes
+    if (![collectionView.delegate conformsToProtocol:@protocol(UICollectionViewDelegateFlowLayout)]) {
+        _attributes = nil;
+        return;
+    }
+    const id<UICollectionViewDelegateFlowLayout> flowDelegate = (id<UICollectionViewDelegateFlowLayout>)collectionView.delegate;
+    
+    // Create the attributes
+    NSMutableDictionary<NSIndexPath *, UICollectionViewLayoutAttributes *> *const attributes = [NSMutableDictionary new];
+    const NSInteger numberOfSections = collectionView.numberOfSections;
+
+    for (NSInteger section = 0; section < numberOfSections; section++) {
+        const NSInteger numberOfItems = [collectionView numberOfItemsInSection:section];
+        for (NSInteger item = 0; item < numberOfItems; item++) {
+            NSIndexPath *const indexPath = [NSIndexPath indexPathForItem:item inSection:section];
+            UICollectionViewLayoutAttributes *const attribute = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
+            const CGSize size = [flowDelegate collectionView:collectionView layout:self sizeForItemAtIndexPath:indexPath];
+            attribute.frame = CGRectMake(0, 0, size.width, size.height);
+            attributes[indexPath] = attribute;
+        }
+    }
+
+    _attributes = [attributes copy];
+}
+
+- (nullable NSArray<__kindof UICollectionViewLayoutAttributes *> *)layoutAttributesForElementsInRect:(CGRect)rect {
+    NSMutableArray<UICollectionViewLayoutAttributes *> *attributes = [NSMutableArray new];
+    [_attributes enumerateKeysAndObjectsUsingBlock:^(NSIndexPath *indexPath, UICollectionViewLayoutAttributes *attribute, BOOL* stop) {
+        if (CGRectIntersectsRect(attribute.frame, rect)) {
+            [attributes addObject:attribute];
+        }
+    }];
+    return [attributes copy];
+}
+
+- (nullable UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath {
+    return _attributes[indexPath];
+}
+
+@end
diff --git a/Tests/Objects/IGTestDelegateDataSource.h b/Tests/Objects/IGTestDelegateDataSource.h
index 99e6f94e..ba82eb34 100644
--- a/Tests/Objects/IGTestDelegateDataSource.h
+++ b/Tests/Objects/IGTestDelegateDataSource.h
@@ -15,6 +15,7 @@
 @class IGTestObject;
 
 extern NSObject *const kIGTestDelegateDataSourceSkipObject;
+extern NSObject *const kIGTestDelegateDataSourceNoSectionControllerSubclass;
 
 @interface IGTestDelegateDataSource : NSObject <IGListTestCaseDataSource>
 
diff --git a/Tests/Objects/IGTestDelegateDataSource.m b/Tests/Objects/IGTestDelegateDataSource.m
index 7a05da69..b6b8d360 100644
--- a/Tests/Objects/IGTestDelegateDataSource.m
+++ b/Tests/Objects/IGTestDelegateDataSource.m
@@ -13,6 +13,7 @@
 #import "IGTestObject.h"
 
 NSObject *const kIGTestDelegateDataSourceSkipObject = @"kIGTestDelegateDataSourceSkipObject";
+NSObject *const kIGTestDelegateDataSourceNoSectionControllerSubclass = @"kIGTestDelegateDataSourceNoSectionControllerSubclass";
 
 @implementation IGTestDelegateDataSource
 
@@ -23,6 +24,8 @@ NSObject *const kIGTestDelegateDataSourceSkipObject = @"kIGTestDelegateDataSourc
 - (IGListSectionController *)listAdapter:(IGListAdapter *)listAdapter sectionControllerForObject:(id)object {
     if ([object isEqual:kIGTestDelegateDataSourceSkipObject]) {
         return nil;
+    } else if ([object isEqual:kIGTestDelegateDataSourceNoSectionControllerSubclass]) {
+        return [IGListSectionController new];
     }
     IGTestDelegateController *sectionController = [[IGTestDelegateController alloc] init];
     sectionController.cellConfigureBlock = self.cellConfigureBlock;