diff --git a/Sources/StructuredQueriesCore/Documentation.docc/Articles/DefiningYourSchema.md b/Sources/StructuredQueriesCore/Documentation.docc/Articles/DefiningYourSchema.md
index 8e6a9720..b84137b0 100644
--- a/Sources/StructuredQueriesCore/Documentation.docc/Articles/DefiningYourSchema.md
+++ b/Sources/StructuredQueriesCore/Documentation.docc/Articles/DefiningYourSchema.md
@@ -51,6 +51,10 @@ To define a Swift data type that represents this table, one can use the `@Table`
 }
 ```
 
+> Note: If your project is using [default main actor isolation] then you further need to annotate
+> your struct as `nonisolated`.
+[default main actor isolation]: https://github.com/swiftlang/swift-evolution/blob/main/proposals/0466-control-default-actor-isolation.md
+
 Note that the struct's field names match the column tables of the table exactly. In order to support
 property names that differ from the columns names, you can use the `@Column` macro. See the section
 below, <doc:DefiningYourSchema#Customizing-a-table>,  for more information on how to customize your
diff --git a/Sources/StructuredQueriesCore/Documentation.docc/Articles/QueryCookbook.md b/Sources/StructuredQueriesCore/Documentation.docc/Articles/QueryCookbook.md
index 85ffa293..5da62973 100644
--- a/Sources/StructuredQueriesCore/Documentation.docc/Articles/QueryCookbook.md
+++ b/Sources/StructuredQueriesCore/Documentation.docc/Articles/QueryCookbook.md
@@ -50,6 +50,10 @@ extension Reminder {
 }
 ```
 
+> Note: If your project is using [default main actor isolation] then you further need to annotate
+> your extension as `nonisolated`, or define the helpers directly in the declaration of the struct.
+[default main actor isolation]: https://github.com/swiftlang/swift-evolution/blob/main/proposals/0466-control-default-actor-isolation.md
+
 Then these helpers can be used when composing together a larger, more complex query. For example,
 we can select all non-deleted lists with the count of all non-deleted reminders in each list like
 so:
@@ -131,6 +135,10 @@ extension Reminder.TableColumns {
 }
 ```
 
+> Note: If your project is using [default main actor isolation] then you further need to annotate
+> your extension as `nonisolated`.
+[default main actor isolation]: https://github.com/swiftlang/swift-evolution/blob/main/proposals/0466-control-default-actor-isolation.md
+
 Then you can use these helpers when building a query. For example, you can use
 ``PrimaryKeyedTableDefinition/count(distinct:filter:)`` to count the number of past due, current and
 scheduled reminders in one single query like so:
diff --git a/Sources/StructuredQueriesSQLiteCore/Documentation.docc/Articles/CustomFunctions.md b/Sources/StructuredQueriesSQLiteCore/Documentation.docc/Articles/CustomFunctions.md
index cb72050a..7d4b76b8 100644
--- a/Sources/StructuredQueriesSQLiteCore/Documentation.docc/Articles/CustomFunctions.md
+++ b/Sources/StructuredQueriesSQLiteCore/Documentation.docc/Articles/CustomFunctions.md
@@ -18,6 +18,10 @@ func exclaim(_ string: String) -> String {
 }
 ```
 
+> Note: If your project is using [default main actor isolation] then you further need to annotate
+> your function as `nonisolated`.
+[default main actor isolation]: https://github.com/swiftlang/swift-evolution/blob/main/proposals/0466-control-default-actor-isolation.md
+
 And will be immediately callable in a query by prefixing the function with `$`:
 
 ```swift
diff --git a/Sources/StructuredQueriesSQLiteMacros/DatabaseFunctionMacro.swift b/Sources/StructuredQueriesSQLiteMacros/DatabaseFunctionMacro.swift
index 5fc5190a..ff0f7bb7 100644
--- a/Sources/StructuredQueriesSQLiteMacros/DatabaseFunctionMacro.swift
+++ b/Sources/StructuredQueriesSQLiteMacros/DatabaseFunctionMacro.swift
@@ -226,12 +226,12 @@ extension DatabaseFunctionMacro: PeerMacro {
 
     return [
       """
-      \(attributes)\(access)\(`static`)var $\(raw: declarationName): \(functionTypeName) {
+      \(attributes)\(access)\(`static`)\(nonisolated)var $\(raw: declarationName): \(functionTypeName) {
       \(functionTypeName)(\(declaration.name.trimmed))
       }
       """,
       """
-      \(attributes)\(access)struct \(functionTypeName): \
+      \(attributes)\(access)\(nonisolated)struct \(functionTypeName): \
       StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
       public typealias Input = \(raw: representableInputType)
       public typealias Output = \(representableOutputType)
diff --git a/Sources/StructuredQueriesSQLiteMacros/Nonisolated.swift b/Sources/StructuredQueriesSQLiteMacros/Nonisolated.swift
new file mode 100644
index 00000000..34418215
--- /dev/null
+++ b/Sources/StructuredQueriesSQLiteMacros/Nonisolated.swift
@@ -0,0 +1,7 @@
+import SwiftSyntax
+
+#if compiler(>=6.1)
+  let nonisolated: TokenSyntax? = .keyword(.nonisolated, trailingTrivia: .space)
+#else
+  let nonisolated: TokenSyntax? = nil
+#endif
diff --git a/Tests/StructuredQueriesMacrosTests/DatabaseFunctionMacroTests.swift b/Tests/StructuredQueriesMacrosTests/DatabaseFunctionMacroTests.swift
index 4ffdce05..09f50bde 100644
--- a/Tests/StructuredQueriesMacrosTests/DatabaseFunctionMacroTests.swift
+++ b/Tests/StructuredQueriesMacrosTests/DatabaseFunctionMacroTests.swift
@@ -19,11 +19,11 @@ extension SnapshotTests {
           Date()
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -71,11 +71,11 @@ extension SnapshotTests {
           Date()
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "current_date"
@@ -123,11 +123,11 @@ extension SnapshotTests {
           strings.map { $0.capitalized }
         }
 
-        var $jsonCapitalize: __macro_local_14jsonCapitalizefMu_ {
+        nonisolated var $jsonCapitalize: __macro_local_14jsonCapitalizefMu_ {
           __macro_local_14jsonCapitalizefMu_(jsonCapitalize)
         }
 
-        struct __macro_local_14jsonCapitalizefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_14jsonCapitalizefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = [String].JSONRepresentation
           public typealias Output = [String].JSONRepresentation
           public let name = "jsonCapitalize"
@@ -181,11 +181,11 @@ extension SnapshotTests {
           42
         }
 
-        var $fortyTwo: __macro_local_8fortyTwofMu_ {
+        nonisolated var $fortyTwo: __macro_local_8fortyTwofMu_ {
           __macro_local_8fortyTwofMu_(fortyTwo)
         }
 
-        struct __macro_local_8fortyTwofMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_8fortyTwofMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Int
           public let name = "fortyTwo"
@@ -233,11 +233,11 @@ extension SnapshotTests {
           dateFormatter.date(from: format)
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = String
           public typealias Output = Date?
           public let name = "currentDate"
@@ -291,11 +291,11 @@ extension SnapshotTests {
           dateFormatter.date(from: format)
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = String
           public typealias Output = Date?
           public let name = "currentDate"
@@ -349,11 +349,11 @@ extension SnapshotTests {
           dateFormatter.date(from: format)
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = String
           public typealias Output = Date?
           public let name = "currentDate"
@@ -407,11 +407,11 @@ extension SnapshotTests {
           dateFormatter.date(from: format)
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = String
           public typealias Output = Date?
           public let name = "currentDate"
@@ -465,11 +465,11 @@ extension SnapshotTests {
           first + second
         }
 
-        var $concat: __macro_local_6concatfMu_ {
+        nonisolated var $concat: __macro_local_6concatfMu_ {
           __macro_local_6concatfMu_(concat)
         }
 
-        struct __macro_local_6concatfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_6concatfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = (String, String)
           public typealias Output = String
           public let name = "concat"
@@ -545,11 +545,11 @@ extension SnapshotTests {
           dateFormatter.date(from: format)
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = String?
           public typealias Output = Date?
           public let name = "currentDate"
@@ -603,11 +603,11 @@ extension SnapshotTests {
           Date()
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -659,11 +659,11 @@ extension SnapshotTests {
           Date()
         }
 
-        var $currentDate: __macro_local_11currentDatefMu_ {
+        nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -715,11 +715,11 @@ extension SnapshotTests {
           Date()
         }
 
-        public var $currentDate: __macro_local_11currentDatefMu_ {
+        public nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        public struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        public nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -767,11 +767,11 @@ extension SnapshotTests {
           Date()
         }
 
-        static var $currentDate: __macro_local_11currentDatefMu_ {
+        static nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -842,11 +842,11 @@ extension SnapshotTests {
           Date()
         }
 
-        @available(*, unavailable) var $currentDate: __macro_local_11currentDatefMu_ {
+        @available(*, unavailable) nonisolated var $currentDate: __macro_local_11currentDatefMu_ {
           __macro_local_11currentDatefMu_(currentDate)
         }
 
-        @available(*, unavailable) struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        @available(*, unavailable) nonisolated struct __macro_local_11currentDatefMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Date
           public let name = "currentDate"
@@ -894,11 +894,11 @@ extension SnapshotTests {
           42
         }
 
-        public var $default: __macro_local_7defaultfMu_ {
+        public nonisolated var $default: __macro_local_7defaultfMu_ {
           __macro_local_7defaultfMu_(`default`)
         }
 
-        public struct __macro_local_7defaultfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        public nonisolated struct __macro_local_7defaultfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Int
           public let name = "default"
@@ -946,11 +946,11 @@ extension SnapshotTests {
           print("...")
         }
 
-        public var $void: __macro_local_4voidfMu_ {
+        public nonisolated var $void: __macro_local_4voidfMu_ {
           __macro_local_4voidfMu_(void)
         }
 
-        public struct __macro_local_4voidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        public nonisolated struct __macro_local_4voidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Swift.Void
           public let name = "void"
@@ -993,11 +993,11 @@ extension SnapshotTests {
           throw Failure()
         }
 
-        public var $void: __macro_local_4voidfMu_ {
+        public nonisolated var $void: __macro_local_4voidfMu_ {
           __macro_local_4voidfMu_(void)
         }
 
-        public struct __macro_local_4voidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        public nonisolated struct __macro_local_4voidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = ()
           public typealias Output = Swift.Void
           public let name = "void"
@@ -1053,11 +1053,11 @@ extension SnapshotTests {
           Swift.min(x, y)
         }
 
-        var $min: __macro_local_3minfMu_ {
+        nonisolated var $min: __macro_local_3minfMu_ {
           __macro_local_3minfMu_(min)
         }
 
-        struct __macro_local_3minfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_3minfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = (Int, Int)
           public typealias Output = Swift.Void
           public let name = "min"
@@ -1120,11 +1120,11 @@ extension SnapshotTests {
           Swift.min(x, y)
         }
 
-        var $min: __macro_local_3minfMu_ {
+        nonisolated var $min: __macro_local_3minfMu_ {
           __macro_local_3minfMu_(min)
         }
 
-        struct __macro_local_3minfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_3minfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = (Int, Int)
           public typealias Output = Swift.Void
           public let name = "min"
@@ -1184,11 +1184,11 @@ extension SnapshotTests {
           !reminder.title.isEmpty || override
         }
 
-        var $isValid: __macro_local_7isValidfMu_ {
+        nonisolated var $isValid: __macro_local_7isValidfMu_ {
           __macro_local_7isValidfMu_(isValid)
         }
 
-        struct __macro_local_7isValidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
+        nonisolated struct __macro_local_7isValidfMu_: StructuredQueriesSQLiteCore.ScalarDatabaseFunction {
           public typealias Input = (Reminder, Bool)
           public typealias Output = Bool
           public let name = "isValid"