diff --git a/Source/Internal/IGListSectionMap.m b/Source/Internal/IGListSectionMap.m
index b5e9f5e7..66a9fded 100644
--- a/Source/Internal/IGListSectionMap.m
+++ b/Source/Internal/IGListSectionMap.m
@@ -45,7 +45,7 @@
     IGParameterAssert(sectionController != nil);
 
     NSNumber *index = [self.sectionControllerToSectionMap objectForKey:sectionController];
-    return index != nil ? [index unsignedIntegerValue] : NSNotFound;
+    return index != nil ? [index integerValue] : NSNotFound;
 }
 
 - (IGListSectionController <IGListSectionType> *)sectionControllerForSection:(NSInteger)section {