diff --git a/Sources/CompletionScoring/Utilities/SwiftExtensions.swift b/Sources/CompletionScoring/Utilities/SwiftExtensions.swift
index 42eeb8cf4..70ab5f4b1 100644
--- a/Sources/CompletionScoring/Utilities/SwiftExtensions.swift
+++ b/Sources/CompletionScoring/Utilities/SwiftExtensions.swift
@@ -232,7 +232,7 @@ extension RandomAccessCollection {
     return body(scratchArea)
   }
 
-  package func concurrentCompactMap<T>(_ f: @Sendable (Element) -> T?) -> [T] where Self: Sendable {
+  package func concurrentCompactMap<T>(_ f: @Sendable (Element) -> T?) -> [T] where Self: Sendable, Index: Sendable {
     return withMapScratchArea { (results: UnsafeMutablePointer<T?>) -> [T] in
       // `nonisolated(unsafe)` is fine because we write to different offsets within the buffer on every concurrent
       // iteration.
@@ -245,7 +245,7 @@ extension RandomAccessCollection {
     }
   }
 
-  package func concurrentMap<T>(_ f: @Sendable (Element) -> T) -> [T] where Self: Sendable {
+  package func concurrentMap<T>(_ f: @Sendable (Element) -> T) -> [T] where Self: Sendable, Index: Sendable {
     return withMapScratchArea { (results: UnsafeMutablePointer<T>) -> [T] in
       // `nonisolated(unsafe)` is fine because we write to different offsets within the buffer on every concurrent
       // iteration.
@@ -290,7 +290,7 @@ protocol ContiguousZeroBasedIndexedCollection: Collection where Index == Int {
 }
 
 extension ContiguousZeroBasedIndexedCollection {
-  func slicedConcurrentForEachSliceRange(body: @Sendable (Range<Index>) -> Void) {
+  func slicedConcurrentForEachSliceRange(body: @Sendable (Range<Index>) -> Void) where Self: SendableMetatype {
     // We want to use `DispatchQueue.concurrentPerform`, but we want to be called only a few times. So that we
     // can amortize per-callback work. We also want to oversubscribe so that we can efficiently use
     // heterogeneous CPUs. If we had 4 efficiency cores, and 4 performance cores, and we dispatched 8 work items
diff --git a/Sources/SKLogging/LoggingScope.swift b/Sources/SKLogging/LoggingScope.swift
index bdd747c0a..c6cc490f5 100644
--- a/Sources/SKLogging/LoggingScope.swift
+++ b/Sources/SKLogging/LoggingScope.swift
@@ -43,7 +43,7 @@ package final class LoggingScope {
 package func withLoggingSubsystemAndScope<Result>(
   subsystem: String,
   scope: String?,
-  @_inheritActorContext _ operation: @Sendable () throws -> Result
+  _ operation: @Sendable () throws -> Result
 ) rethrows -> Result {
   return try LoggingScope.$_subsystem.withValue(subsystem) {
     return try LoggingScope.$_scope.withValue(scope, operation: operation)
diff --git a/Sources/SourceKitLSP/Swift/CodeActions/SyntaxCodeActionProvider.swift b/Sources/SourceKitLSP/Swift/CodeActions/SyntaxCodeActionProvider.swift
index 4ed0f42eb..07f2212c1 100644
--- a/Sources/SourceKitLSP/Swift/CodeActions/SyntaxCodeActionProvider.swift
+++ b/Sources/SourceKitLSP/Swift/CodeActions/SyntaxCodeActionProvider.swift
@@ -17,7 +17,7 @@ import SwiftSyntax
 
 /// Describes types that provide one or more code actions based on purely
 /// syntactic information.
-protocol SyntaxCodeActionProvider {
+protocol SyntaxCodeActionProvider: SendableMetatype {
   /// Produce code actions within the given scope. Each code action
   /// corresponds to one syntactic transformation that can be performed, such
   /// as adding or removing separators from an integer literal.
diff --git a/Sources/SwiftExtensions/AsyncUtils.swift b/Sources/SwiftExtensions/AsyncUtils.swift
index cc587e769..eeed7570e 100644
--- a/Sources/SwiftExtensions/AsyncUtils.swift
+++ b/Sources/SwiftExtensions/AsyncUtils.swift
@@ -132,7 +132,7 @@ package func withCancellableCheckedThrowingContinuation<Handle: Sendable, Result
   )
 }
 
-extension Collection where Element: Sendable {
+extension Collection where Self: Sendable, Element: Sendable {
   /// Transforms all elements in the collection concurrently and returns the transformed collection.
   package func concurrentMap<TransformedElement: Sendable>(
     maxConcurrentTasks: Int = ProcessInfo.processInfo.processorCount,
diff --git a/Tests/BuildSystemIntegrationTests/SwiftPMBuildSystemTests.swift b/Tests/BuildSystemIntegrationTests/SwiftPMBuildSystemTests.swift
index 58dc68d26..2db01daf9 100644
--- a/Tests/BuildSystemIntegrationTests/SwiftPMBuildSystemTests.swift
+++ b/Tests/BuildSystemIntegrationTests/SwiftPMBuildSystemTests.swift
@@ -770,7 +770,7 @@ struct SwiftPMBuildSystemTests {
       // We opened the project from a symlink. The realpath isn't part of the project and we should thus not receive
       // build settings for it.
       #expect(
-        try await #require(
+        try #require(
           await buildSystemManager.buildSettingsInferredFromMainFile(
             for: DocumentURI(aswiftReal),
             language: .swift,