diff --git a/Sources/DataSources/ASCollectionNode+Rx/ASCollectionSectionedDataSource.swift b/Sources/DataSources/ASCollectionNode+Rx/ASCollectionSectionedDataSource.swift
index a293fc2..010f705 100644
--- a/Sources/DataSources/ASCollectionNode+Rx/ASCollectionSectionedDataSource.swift
+++ b/Sources/DataSources/ASCollectionNode+Rx/ASCollectionSectionedDataSource.swift
@@ -29,11 +29,14 @@ open class ASCollectionSectionedDataSource<S: SectionModelType>: NSObject, ASCol
     }
 
     fileprivate static func configureCellBlockNotSet(dataSource: ASCollectionSectionedDataSource<S>, node: ASCollectionNode, indexPath: IndexPath, model: I) -> ASCellNodeBlock {
-        return { dataSource.collectionNode(node, nodeForItemAt: indexPath) }
+        // Users expect collectionNode(_:nodeForItemAt:) will be executed in main thread
+        let cellNode = dataSource.collectionNode(node, nodeForItemAt: indexPath)
+        return { cellNode }
     }
 
     fileprivate static func configureSupplementaryViewBlockNotSet(dataSource: ASCollectionSectionedDataSource<S>, node: ASCollectionNode, nodeForSupplementaryElementOfKind kind: String, indexPath: IndexPath) -> ASCellNodeBlock {
-        return { dataSource.collectionNode(node, nodeForSupplementaryElementOfKind: kind, at: indexPath) }
+        // Users expect collectionNode(_nodeForSupplementaryElementOfKind:at:) will be executed in main thread according to api doc.
+        return { DispatchQueue.main.sync(execute: { dataSource.collectionNode(node, nodeForSupplementaryElementOfKind: kind, at: indexPath) }) }
     }
 
     public init(
diff --git a/Sources/DataSources/ASTableNode+Rx/ASTableSectionedDataSource.swift b/Sources/DataSources/ASTableNode+Rx/ASTableSectionedDataSource.swift
index e39932c..1a15674 100644
--- a/Sources/DataSources/ASTableNode+Rx/ASTableSectionedDataSource.swift
+++ b/Sources/DataSources/ASTableNode+Rx/ASTableSectionedDataSource.swift
@@ -35,7 +35,9 @@ open class ASTableSectionedDataSource<S: SectionModelType>: NSObject, ASTableDat
     }
 
     fileprivate static func configureCellBlockNotSet(dataSource: ASTableSectionedDataSource<S>, node: ASTableNode, indexPath: IndexPath, model: I) -> ASCellNodeBlock {
-        return { dataSource.tableNode(node, nodeForRowAt: indexPath) }
+        // Users expect taleNode(_:nodeForRowAt:) will be executed in main thread
+        let cellNode = dataSource.tableNode(node, nodeForRowAt: indexPath)
+        return { cellNode }
     }
 
     #if os(iOS)
diff --git a/Sources/DataSources/ASTableNode+Rx/RxASTableAnimatedDataSource.swift b/Sources/DataSources/ASTableNode+Rx/RxASTableAnimatedDataSource.swift
index 0a64996..8cf9269 100644
--- a/Sources/DataSources/ASTableNode+Rx/RxASTableAnimatedDataSource.swift
+++ b/Sources/DataSources/ASTableNode+Rx/RxASTableAnimatedDataSource.swift
@@ -150,6 +150,6 @@ open class RxASTableAnimatedDataSource<S: AnimatableSectionModelType>: ASTableSe
                     tableNode.reloadData()
                 }
             }
-            }.on(observedEvent)
+        }.on(observedEvent)
     }
 }
diff --git a/Sources/DataSources/ASTableNode+Rx/RxASTableReloadDataSource.swift b/Sources/DataSources/ASTableNode+Rx/RxASTableReloadDataSource.swift
index 365ab88..08b1cd3 100644
--- a/Sources/DataSources/ASTableNode+Rx/RxASTableReloadDataSource.swift
+++ b/Sources/DataSources/ASTableNode+Rx/RxASTableReloadDataSource.swift
@@ -29,6 +29,6 @@ open class RxASTableReloadDataSource<S: SectionModelType>: ASTableSectionedDataS
                 dataSource.setSections(element)
                 tableNode.reloadData()
             }
-            }.on(observedEvent)
+        }.on(observedEvent)
     }
 }