diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ce21c7d..386c826 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,6 +27,7 @@ jobs:
             "509.0.0..<510.0.0",
             "510.0.0..<511.0.0",
             "511.0.0..<601.0.0",
+            "601.0.0..<602.0.0",
           ]
 
     steps:
diff --git a/Package.resolved b/Package.resolved
index 80436bf..41575b3 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -14,8 +14,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/swift-snapshot-testing",
       "state" : {
-        "revision" : "b2d4cb30735f4fbc3a01963a9c658336dd21e9ba",
-        "version" : "1.18.1"
+        "revision" : "37230a37e83f1b7023be08e1b1a2603fcb1567fb",
+        "version" : "1.18.4"
       }
     },
     {
@@ -23,8 +23,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/swiftlang/swift-syntax",
       "state" : {
-        "revision" : "0687f71944021d616d34d922343dcef086855920",
-        "version" : "600.0.1"
+        "revision" : "f99ae8aa18f0cf0d53481901f88a0991dc3bd4a2",
+        "version" : "601.0.1"
       }
     },
     {
diff --git a/Package.swift b/Package.swift
index 7914132..222709c 100644
--- a/Package.swift
+++ b/Package.swift
@@ -30,7 +30,7 @@ let package = Package(
     .conditionalPackage(
       url: "https://github.com/swiftlang/swift-syntax",
       envVar: "SWIFT_SYNTAX_VERSION",
-      default: "509.0.0..<601.0.0"
+      default: "509.0.0..<602.0.0"
     ),
   ],
   targets: [
diff --git a/Sources/MacroTesting/AssertMacro.swift b/Sources/MacroTesting/AssertMacro.swift
index 6dc5f86..04dc830 100644
--- a/Sources/MacroTesting/AssertMacro.swift
+++ b/Sources/MacroTesting/AssertMacro.swift
@@ -549,14 +549,14 @@ public func assertMacro(
   }
 }
 
-// From: https://github.com/apple/swift-syntax/blob/d647052/Sources/SwiftSyntaxMacrosTestSupport/Assertions.swift
-extension FixIt.Change {
+// From: https://github.com/swiftlang/swift-syntax/blob/601.0.1/Sources/SwiftSyntaxMacrosGenericTestSupport/Assertions.swift
+fileprivate extension FixIt.Change {
   /// Returns the edit for this change, translating positions from detached nodes
   /// to the corresponding locations in the original source file based on
   /// `expansionContext`.
   ///
   /// - SeeAlso: `FixIt.Change.edit`
-  fileprivate func edit(in expansionContext: BasicMacroExpansionContext) -> SourceEdit {
+  func edit(in expansionContext: BasicMacroExpansionContext) -> SourceEdit {
     switch self {
     case .replace(let oldNode, let newNode):
       let start = expansionContext.position(of: oldNode.position, anchoredAt: oldNode)
@@ -568,21 +568,30 @@ extension FixIt.Change {
 
     case .replaceLeadingTrivia(let token, let newTrivia):
       let start = expansionContext.position(of: token.position, anchoredAt: token)
-      let end = expansionContext.position(
-        of: token.positionAfterSkippingLeadingTrivia, anchoredAt: token)
+      let end = expansionContext.position(of: token.positionAfterSkippingLeadingTrivia, anchoredAt: token)
       return SourceEdit(
         range: start..<end,
         replacement: newTrivia.description
       )
 
     case .replaceTrailingTrivia(let token, let newTrivia):
-      let start = expansionContext.position(
-        of: token.endPositionBeforeTrailingTrivia, anchoredAt: token)
+      let start = expansionContext.position(of: token.endPositionBeforeTrailingTrivia, anchoredAt: token)
       let end = expansionContext.position(of: token.endPosition, anchoredAt: token)
       return SourceEdit(
         range: start..<end,
         replacement: newTrivia.description
       )
+
+#if canImport(SwiftSyntax601)
+    case .replaceChild(let replacingChildData):
+      let range = replacingChildData.replacementRange
+      let start = expansionContext.position(of: range.lowerBound, anchoredAt: replacingChildData.parent)
+      let end = expansionContext.position(of: range.upperBound, anchoredAt: replacingChildData.parent)
+      return SourceEdit(
+        range: start..<end,
+        replacement: replacingChildData.newChild.description
+      )
+#endif
     }
   }
 }
diff --git a/Tests/MacroTestingTests/MacroExamples/AddAsyncMacro.swift b/Tests/MacroTestingTests/MacroExamples/AddAsyncMacro.swift
index 13d32d6..940b3b8 100644
--- a/Tests/MacroTestingTests/MacroExamples/AddAsyncMacro.swift
+++ b/Tests/MacroTestingTests/MacroExamples/AddAsyncMacro.swift
@@ -74,7 +74,7 @@ public struct AddAsyncMacro: PeerMacro {
     let isResultReturn = returnType?.children(viewMode: .all).first?.description == "Result"
     let successReturnType =
       isResultReturn
-      ? returnType!.as(IdentifierTypeSyntax.self)!.genericArgumentClause?.arguments.first!.argument
+      ? returnType!.as(IdentifierTypeSyntax.self)!.genericArgumentClause?.arguments.first!.argumentCompat600
       : returnType
 
     // Remove completionHandler and comma from the previous parameter
diff --git a/Tests/MacroTestingTests/MacroExamples/OptionSetMacro.swift b/Tests/MacroTestingTests/MacroExamples/OptionSetMacro.swift
index f2db89f..49c7b3e 100644
--- a/Tests/MacroTestingTests/MacroExamples/OptionSetMacro.swift
+++ b/Tests/MacroTestingTests/MacroExamples/OptionSetMacro.swift
@@ -129,7 +129,7 @@ public struct OptionSetMacro {
     guard
       let genericArgs = attribute.attributeName.as(IdentifierTypeSyntax.self)?
         .genericArgumentClause,
-      let rawType = genericArgs.arguments.first?.argument
+      let rawType = genericArgs.arguments.first?.argumentCompat600
     else {
       context.diagnose(OptionSetMacroDiagnostic.requiresOptionsEnumRawType.diagnose(at: attribute))
       return nil
diff --git a/Tests/MacroTestingTests/SwiftSyntaxCompatibilityHelpers.swift b/Tests/MacroTestingTests/SwiftSyntaxCompatibilityHelpers.swift
new file mode 100644
index 0000000..77adc13
--- /dev/null
+++ b/Tests/MacroTestingTests/SwiftSyntaxCompatibilityHelpers.swift
@@ -0,0 +1,11 @@
+import SwiftSyntax
+
+extension GenericArgumentSyntax {
+    var argumentCompat600: TypeSyntax? {
+#if canImport(SwiftSyntax601)
+        argument.as(TypeSyntax.self)
+#else
+        argument
+#endif
+    }
+}