diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2bb8181d..6fc725c8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -59,6 +59,7 @@ jobs:
       matrix:
         swift:
           - '5.10'
+          - '6.0'
     name: Ubuntu (Swift ${{ matrix.swift }})
     runs-on: ubuntu-latest
     container: swift:${{ matrix.swift }}
diff --git a/Package.resolved b/Package.resolved
index 0c1bf166..ed9a1fdb 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,13 +1,13 @@
 {
-  "originHash" : "46c7c52f0c1617cc1d5bc47663541c21a6e6734ddf2ad859bf5bf5bc207fa8f4",
+  "originHash" : "b0e46c8707f648cbd1d708418b9df17059d230dae6d9892053bdfb8d1d11715b",
   "pins" : [
     {
       "identity" : "combine-schedulers",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/combine-schedulers",
       "state" : {
-        "revision" : "9fa31f4403da54855f1e2aeaeff478f4f0e40b13",
-        "version" : "1.0.2"
+        "revision" : "5928286acce13def418ec36d05a001a9641086f2",
+        "version" : "1.0.3"
       }
     },
     {
@@ -15,8 +15,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/swift-clocks",
       "state" : {
-        "revision" : "b9b24b69e2adda099a1fa381cda1eeec272d5b53",
-        "version" : "1.0.5"
+        "revision" : "cc46202b53476d64e824e0b6612da09d84ffde8e",
+        "version" : "1.0.6"
       }
     },
     {
@@ -24,8 +24,17 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/swift-concurrency-extras",
       "state" : {
-        "revision" : "bb5059bde9022d69ac516803f4f227d8ac967f71",
-        "version" : "1.1.0"
+        "revision" : "82a4ae7170d98d8538ec77238b7eb8e7199ef2e8",
+        "version" : "1.3.1"
+      }
+    },
+    {
+      "identity" : "swift-custom-dump",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/pointfreeco/swift-custom-dump",
+      "state" : {
+        "revision" : "82645ec760917961cfa08c9c0c7104a57a0fa4b1",
+        "version" : "1.3.3"
       }
     },
     {
@@ -33,8 +42,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-docc-plugin",
       "state" : {
-        "revision" : "2eb22993b3dfd0c0d32729b357c8dabb6cd44680",
-        "version" : "1.4.2"
+        "revision" : "85e4bb4e1cd62cec64a4b8e769dcefdf0c5b9d64",
+        "version" : "1.4.3"
       }
     },
     {
@@ -51,8 +60,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/swift-macro-testing",
       "state" : {
-        "revision" : "20c1a8f3b624fb5d1503eadcaa84743050c350f4",
-        "version" : "0.5.2"
+        "revision" : "0b80a098d4805a21c412b65f01ffde7b01aab2fa",
+        "version" : "0.6.0"
       }
     },
     {
@@ -60,8 +69,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/swift-snapshot-testing",
       "state" : {
-        "revision" : "6d932a79e7173b275b96c600c86c603cf84f153c",
-        "version" : "1.17.4"
+        "revision" : "b2d4cb30735f4fbc3a01963a9c658336dd21e9ba",
+        "version" : "1.18.1"
       }
     },
     {
@@ -69,8 +78,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/swiftlang/swift-syntax",
       "state" : {
-        "revision" : "cb53fa1bd3219b0b23ded7dfdd3b2baff266fd25",
-        "version" : "600.0.0"
+        "revision" : "0687f71944021d616d34d922343dcef086855920",
+        "version" : "600.0.1"
       }
     },
     {
@@ -78,8 +87,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/pointfreeco/xctest-dynamic-overlay",
       "state" : {
-        "revision" : "770f990d3e4eececb57ac04a6076e22f8c97daeb",
-        "version" : "1.4.2"
+        "revision" : "39de59b2d47f7ef3ca88a039dff3084688fe27f4",
+        "version" : "1.5.2"
       }
     }
   ],
diff --git a/Sources/Dependencies/DependencyValues.swift b/Sources/Dependencies/DependencyValues.swift
index 69e19b00..ba51b626 100644
--- a/Sources/Dependencies/DependencyValues.swift
+++ b/Sources/Dependencies/DependencyValues.swift
@@ -149,7 +149,7 @@ public struct DependencyValues: Sendable {
             .takeUnretainedValue()
         else { return }
         let testCaseWillStartBlock: @convention(block) (AnyObject) -> Void = { _ in
-          DependencyValues._current.cachedValues.cached = [:]
+          DependencyValues._current.cachedValues.resetCache()
         }
         let testCaseWillStartImp = imp_implementationWithBlock(testCaseWillStartBlock)
         class_addMethod(
@@ -167,7 +167,7 @@ public struct DependencyValues: Sendable {
       if isTesting {
         XCTestObservationCenter.shared.addTestObserver(
           TestObserver {
-            DependencyValues._current.cachedValues.cached = [:]
+            DependencyValues._current.cachedValues.resetCache()
           }
         )
       }
@@ -191,7 +191,7 @@ public struct DependencyValues: Sendable {
         }
       #endif
       pRegisterTestObserver?({
-        DependencyValues._current.cachedValues.cached = [:]
+        DependencyValues._current.cachedValues.resetCache()
       })
     #endif
   }
@@ -286,6 +286,8 @@ public struct DependencyValues: Sendable {
           reportIssue("Ignoring dependencies prepared in preview app entry point")
           return
         }
+        cachedValues.lock.lock()
+        defer { cachedValues.lock.unlock() }
         let cacheKey = CachedValues.CacheKey(id: TypeIdentifier(key), context: context)
         guard !cachedValues.cached.keys.contains(cacheKey) else {
           if cachedValues.cached[cacheKey]?.preparationID != DependencyValues.preparationID {
@@ -405,7 +407,7 @@ public struct DependencyValues: Sendable {
     message: "'resetCache' is no longer necessary for most (unparameterized) '@Test' cases"
   )
   public func resetCache() {
-    cachedValues.cached = [:]
+    cachedValues.resetCache()
   }
 }
 
@@ -478,9 +480,15 @@ public final class CachedValues: @unchecked Sendable {
     let preparationID: UUID?
   }
 
-  private let lock = NSRecursiveLock()
+  public let lock = NSRecursiveLock()
   public var cached = [CacheKey: CachedValue]()
 
+  public func resetCache() {
+    lock.lock()
+    defer { lock.unlock() }
+    cached = [:]
+  }
+
   func value<Key: TestDependencyKey>(
     for key: Key.Type,
     context: DependencyContext,
diff --git a/Tests/DependenciesTests/CacheTests.swift b/Tests/DependenciesTests/CacheTests.swift
index ef06cc2d..76757040 100644
--- a/Tests/DependenciesTests/CacheTests.swift
+++ b/Tests/DependenciesTests/CacheTests.swift
@@ -5,7 +5,7 @@ final class CachedValueTests: XCTestCase {
   override func tearDown() {
     super.tearDown()
     CacheLocals.$skipFailure.withValue(true) {
-      DependencyValues._current.cachedValues.cached = [:]
+      DependencyValues._current.cachedValues.resetCache()
     }
   }
 
diff --git a/Tests/DependenciesTests/DependencyValuesTests.swift b/Tests/DependenciesTests/DependencyValuesTests.swift
index b2e0710a..046841df 100644
--- a/Tests/DependenciesTests/DependencyValuesTests.swift
+++ b/Tests/DependenciesTests/DependencyValuesTests.swift
@@ -437,30 +437,33 @@ final class DependencyValuesTests: XCTestCase {
       self.wait(for: [expectation], timeout: 1)
     }
 
-    @MainActor
-    func testEscapingInFeatureModel_InstanceVariablePropagated() async {
-      let expectation = self.expectation(description: "escape")
-
+    // TODO: Remove this condition when Linux CI is updated to a more recent Swift 6.
+    #if !os(Linux) || compiler(<6)
       @MainActor
-      class FeatureModel /*: ObservableObject*/ {
-        @Dependency(\.fullDependency) var fullDependency
-        func doSomething(expectation: XCTestExpectation) {
-          DispatchQueue.main.async {
-            XCTAssertEqual(self.fullDependency.value, 42)
-            expectation.fulfill()
+      func testEscapingInFeatureModel_InstanceVariablePropagated() async {
+        let expectation = self.expectation(description: "escape")
+
+        @MainActor
+        class FeatureModel /*: ObservableObject*/ {
+          @Dependency(\.fullDependency) var fullDependency
+          func doSomething(expectation: XCTestExpectation) {
+            DispatchQueue.main.async {
+              XCTAssertEqual(self.fullDependency.value, 42)
+              expectation.fulfill()
+            }
           }
         }
-      }
 
-      let model = withDependencies {
-        $0.fullDependency.value = 42
-      } operation: {
-        FeatureModel()
-      }
+        let model = withDependencies {
+          $0.fullDependency.value = 42
+        } operation: {
+          FeatureModel()
+        }
 
-      model.doSomething(expectation: expectation)
-      await fulfillment(of: [expectation], timeout: 1)
-    }
+        model.doSomething(expectation: expectation)
+        await fulfillment(of: [expectation], timeout: 1)
+      }
+    #endif
 
     func testEscapingInFeatureModel_NotPropagated() async {
       let expectation = self.expectation(description: "escape")