diff --git a/Package.resolved b/Package.resolved
index 2b21f9e..d659657 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/mxcl/PromiseKit.git",
         "state": {
           "branch": null,
-          "revision": "44402644d7973879153784b02c0745de32634a35",
-          "version": "6.15.2"
+          "revision": "cb70b070cde06837cd10a1febdf6105c1a3bb348",
+          "version": "8.1.1"
         }
       }
     ]
diff --git a/Package.swift b/Package.swift
index 6072eb0..95fdb57 100644
--- a/Package.swift
+++ b/Package.swift
@@ -3,7 +3,7 @@ import PackageDescription
 let package = Package(
     name: "PMKFoundation",
     dependencies: [
-        .Package(url: "https://github.com/mxcl/PromiseKit.git", majorVersion: 6)
+        .Package(url: "https://github.com/mxcl/PromiseKit.git", majorVersion: 8)
     ],
     swiftLanguageVersions: [3, 4],
     exclude: [
diff --git a/Package@swift-4.2.swift b/Package@swift-4.2.swift
index 2b8df6a..f238fe0 100644
--- a/Package@swift-4.2.swift
+++ b/Package@swift-4.2.swift
@@ -7,7 +7,7 @@ pkg.products = [
     .library(name: "PMKFoundation", targets: ["PMKFoundation"]),
 ]
 pkg.dependencies = [
-    .package(url: "https://github.com/mxcl/PromiseKit.git", .upToNextMajor(from: "6.0.0"))
+    .package(url: "https://github.com/mxcl/PromiseKit.git", .upToNextMajor(from: "8.0.0"))
 ]
 pkg.swiftLanguageVersions = [.v3, .v4, .v4_2, .version("5")]
 
diff --git a/Package@swift-5.0.swift b/Package@swift-5.0.swift
index 9800d38..5b35dfd 100644
--- a/Package@swift-5.0.swift
+++ b/Package@swift-5.0.swift
@@ -7,7 +7,7 @@ pkg.products = [
     .library(name: "PMKFoundation", targets: ["PMKFoundation"]),
 ]
 pkg.dependencies = [
-    .package(url: "https://github.com/mxcl/PromiseKit.git", from: "6.8.3")
+    .package(url: "https://github.com/mxcl/PromiseKit.git", from: "8.0.0")
 ]
 pkg.swiftLanguageVersions = [.v4, .v4_2, .v5]
 
diff --git a/Package@swift-5.3.swift b/Package@swift-5.3.swift
index 5d2a31a..9c46259 100644
--- a/Package@swift-5.3.swift
+++ b/Package@swift-5.3.swift
@@ -7,7 +7,7 @@ pkg.products = [
     .library(name: "PMKFoundation", targets: ["PMKFoundation"]),
 ]
 pkg.dependencies = [
-    .package(url: "https://github.com/mxcl/PromiseKit.git", from: "6.8.3")
+    .package(url: "https://github.com/mxcl/PromiseKit.git", from: "8.0.0")
 ]
 pkg.swiftLanguageVersions = [.v4, .v4_2, .v5]