diff --git a/Brief/Updater.swift b/Brief/Updater.swift
index 010cb14..cea0bbb 100644
--- a/Brief/Updater.swift
+++ b/Brief/Updater.swift
@@ -11,7 +11,10 @@ public class Updater: ObservableObject, UpdaterProtocol {
 
     @Published public var update: Release?
 
-    public init(checkOnLaunch: Bool) {
+    private let osVersion: SemVer
+
+    public init(checkOnLaunch: Bool, osVersion: SemVer = SemVer(ProcessInfo.processInfo.operatingSystemVersion)) {
+        self.osVersion = osVersion
         if checkOnLaunch {
             // Don't do a launch check if the user hasn't seen the setup prompt explaining updater yet.
             checkForUpdates()
@@ -25,8 +28,8 @@ public class Updater: ObservableObject, UpdaterProtocol {
     public func checkForUpdates() {
         URLSession.shared.dataTask(with: Constants.updateURL) { data, _, _ in
             guard let data = data else { return }
-            guard let release = try? JSONDecoder().decode(Release.self, from: data) else { return }
-            self.evaluate(release: release)
+            guard let releases = try? JSONDecoder().decode([Release].self, from: data) else { return }
+            self.evaluate(releases: releases)
         }.resume()
     }
 
@@ -42,11 +45,16 @@ public class Updater: ObservableObject, UpdaterProtocol {
 
 extension Updater {
 
-    func evaluate(release: Release) {
+    func evaluate(releases: [Release]) {
+        guard let release = releases
+                .sorted()
+                .reversed()
+                .filter({ !$0.prerelease })
+                .first(where: { $0.minimumOSVersion <= osVersion }) else { return }
         guard !userIgnored(release: release) else { return }
         guard !release.prerelease else { return }
         let latestVersion = SemVer(release.name)
-        let currentVersion = SemVer(Bundle.main.infoDictionary!["CFBundleShortVersionString"] as! String)
+        let currentVersion = SemVer(Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "0.0.0")
         if latestVersion > currentVersion {
             DispatchQueue.main.async {
                 self.update = release
@@ -64,11 +72,11 @@ extension Updater {
     }
 }
 
-struct SemVer {
+public struct SemVer {
 
     let versionNumbers: [Int]
 
-    init(_ version: String) {
+    public init(_ version: String) {
         // Betas have the format 1.2.3_beta1
         let strippedBeta = version.split(separator: "_").first!
         var split = strippedBeta.split(separator: ".").compactMap { Int($0) }
@@ -78,11 +86,15 @@ struct SemVer {
         versionNumbers = split
     }
 
+    public init(_ version: OperatingSystemVersion) {
+        versionNumbers = [version.majorVersion, version.minorVersion, version.patchVersion]
+    }
+
 }
 
 extension SemVer: Comparable {
 
-    static func < (lhs: SemVer, rhs: SemVer) -> Bool {
+    public static func < (lhs: SemVer, rhs: SemVer) -> Bool {
         for (latest, current) in zip(lhs.versionNumbers, rhs.versionNumbers) {
             if latest < current {
                 return true
@@ -99,7 +111,7 @@ extension SemVer: Comparable {
 extension Updater {
 
     enum Constants {
-        static let updateURL = URL(string: "https://api.github.com/repos/maxgoedjen/secretive/releases/latest")!
+        static let updateURL = URL(string: "https://api.github.com/repos/maxgoedjen/secretive/releases")!
     }
 
 }
@@ -128,12 +140,32 @@ extension Release: Identifiable {
 
 }
 
+extension Release: Comparable {
+
+    public static func < (lhs: Release, rhs: Release) -> Bool {
+        lhs.version < rhs.version
+    }
+
+}
+
 extension Release {
 
     public var critical: Bool {
         body.contains(Constants.securityContent)
     }
 
+    public var version: SemVer {
+        SemVer(name)
+    }
+
+    public var minimumOSVersion: SemVer {
+        guard let range = body.range(of: "Minimum macOS Version"),
+              let numberStart = body.rangeOfCharacter(from: CharacterSet.decimalDigits, options: [], range: range.upperBound..<body.endIndex) else { return SemVer("11.0.0") }
+        let numbersEnd = body.rangeOfCharacter(from: CharacterSet.whitespacesAndNewlines, options: [], range: numberStart.upperBound..<body.endIndex)?.lowerBound ?? body.endIndex
+        let version = numberStart.lowerBound..<numbersEnd
+        return SemVer(String(body[version]))
+    }
+
 }
 
 extension Release {
diff --git a/BriefTests/ReleaseParsingTests.swift b/BriefTests/ReleaseParsingTests.swift
new file mode 100644
index 0000000..f3e0803
--- /dev/null
+++ b/BriefTests/ReleaseParsingTests.swift
@@ -0,0 +1,104 @@
+import XCTest
+@testable import Brief
+
+class ReleaseParsingTests: XCTestCase {
+
+    func testNonCritical() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Initial release")
+        XCTAssert(release.critical == false)
+    }
+
+    func testCritical() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update")
+        XCTAssert(release.critical == true)
+    }
+
+    func testOSMissing() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update")
+        XCTAssert(release.minimumOSVersion == SemVer("11.0.0"))
+    }
+
+    func testOSPresentWithContentBelow() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update ##Minimum macOS Version\n1.2.3\nBuild info")
+        XCTAssert(release.minimumOSVersion == SemVer("1.2.3"))
+    }
+
+    func testOSPresentAtEnd() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update Minimum macOS Version: 1.2.3")
+        XCTAssert(release.minimumOSVersion == SemVer("1.2.3"))
+    }
+
+    func testOSWithMacOSPrefix() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update Minimum macOS Version: macOS 1.2.3")
+        XCTAssert(release.minimumOSVersion == SemVer("1.2.3"))
+    }
+
+    func testOSGreaterThanMinimum() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update Minimum macOS Version: 1.2.3")
+        XCTAssert(release.minimumOSVersion < SemVer("11.0.0"))
+    }
+
+    func testOSEqualToMinimum() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update Minimum macOS Version: 11.2.3")
+        XCTAssert(release.minimumOSVersion <= SemVer("11.2.3"))
+    }
+
+    func testOSLessThanMinimum() {
+        let release = Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Critical Security Update Minimum macOS Version: 1.2.3")
+        XCTAssert(release.minimumOSVersion > SemVer("1.0.0"))
+    }
+
+    func testGreatestSelectedIfOldPatchIsPublishedLater() {
+        // If 2.x.x series has been published, and a patch for 1.x.x is issued
+        // 2.x.x should still be selected if user can run it.
+        let updater = Updater(checkOnLaunch: false, osVersion: SemVer("2.2.3"))
+        let two = Release(name: "2.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "2.0 available! Minimum macOS Version: 2.2.3")
+        let releases = [
+            Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Initial release Minimum macOS Version: 1.2.3"),
+            Release(name: "1.0.1", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Bug fixes Minimum macOS Version: 1.2.3"),
+            two,
+            Release(name: "1.0.2", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Emergency patch! Minimum macOS Version: 1.2.3"),
+        ]
+
+        let expectation = XCTestExpectation()
+        updater.evaluate(releases: releases)
+        DispatchQueue.main.async {
+            XCTAssert(updater.update == two)
+            expectation.fulfill()
+        }
+        wait(for: [expectation], timeout: 1)
+    }
+
+    func testLatestVersionIsRunnable() {
+        // If the 2.x.x series has been published but the user can't run it
+        // the last version the user can run should be selected.
+        let updater = Updater(checkOnLaunch: false, osVersion: SemVer("1.2.3"))
+        let oneOhTwo = Release(name: "1.0.2", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Emergency patch! Minimum macOS Version: 1.2.3")
+        let releases = [
+            Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Initial release Minimum macOS Version: 1.2.3"),
+            Release(name: "1.0.1", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Bug fixes Minimum macOS Version: 1.2.3"),
+            Release(name: "2.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "2.0 available! Minimum macOS Version: 2.2.3"),
+            Release(name: "1.0.2", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Emergency patch! Minimum macOS Version: 1.2.3"),
+        ]
+        let expectation = XCTestExpectation()
+        updater.evaluate(releases: releases)
+        DispatchQueue.main.async {
+            XCTAssert(updater.update == oneOhTwo)
+            expectation.fulfill()
+        }
+        wait(for: [expectation], timeout: 1)
+    }
+
+    func testSorting() {
+        let two = Release(name: "2.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "2.0 available!")
+        let releases = [
+            Release(name: "1.0.0", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Initial release"),
+            Release(name: "1.0.1", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Bug fixes"),
+            two,
+            Release(name: "1.0.2", prerelease: false, html_url: URL(string: "https://example.com")!, body: "Emergency patch!"),
+        ]
+        let sorted = releases.sorted().reversed().first
+        XCTAssert(sorted == two)
+    }
+
+}
diff --git a/BriefTests/BriefTests.swift b/BriefTests/SemVerTests.swift
similarity index 68%
rename from BriefTests/BriefTests.swift
rename to BriefTests/SemVerTests.swift
index 02729fa..f7ee332 100644
--- a/BriefTests/BriefTests.swift
+++ b/BriefTests/SemVerTests.swift
@@ -27,6 +27,21 @@ class SemVerTests: XCTestCase {
         XCTAssert(current < new)
     }
 
+    func testRegularParsing() {
+        let current = SemVer("1.0.2")
+        XCTAssert(current.versionNumbers == [1, 0, 2])
+    }
+
+    func testNoPatch() {
+        let current = SemVer("1.1")
+        XCTAssert(current.versionNumbers == [1, 1, 0])
+    }
+
+    func testGarbage() {
+        let current = SemVer("Test")
+        XCTAssert(current.versionNumbers == [0, 0, 0])
+    }
+
     func testBeta() {
         let current = SemVer("1.0.2")
         let new = SemVer("1.1.0_beta1")
diff --git a/Secretive.xcodeproj/project.pbxproj b/Secretive.xcodeproj/project.pbxproj
index cad1ecf..70a3fbf 100644
--- a/Secretive.xcodeproj/project.pbxproj
+++ b/Secretive.xcodeproj/project.pbxproj
@@ -64,7 +64,7 @@
 		508BF28E25B4F005009EFB7E /* InternetAccessPolicy.plist in Resources */ = {isa = PBXBuildFile; fileRef = 508BF28D25B4F005009EFB7E /* InternetAccessPolicy.plist */; };
 		508BF2AA25B4F1CB009EFB7E /* InternetAccessPolicy.plist in Resources */ = {isa = PBXBuildFile; fileRef = 508BF29425B4F140009EFB7E /* InternetAccessPolicy.plist */; };
 		5091D2BC25183B830049FD9B /* ApplicationDirectoryController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5091D2BB25183B830049FD9B /* ApplicationDirectoryController.swift */; };
-		5091D3222519D56D0049FD9B /* BriefTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5091D3212519D56D0049FD9B /* BriefTests.swift */; };
+		5091D3222519D56D0049FD9B /* SemVerTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5091D3212519D56D0049FD9B /* SemVerTests.swift */; };
 		5091D3242519D56D0049FD9B /* Brief.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 506772FB2426F3F400034DED /* Brief.framework */; };
 		5099A02423FD2AAA0062B6F2 /* CreateSecretView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5099A02323FD2AAA0062B6F2 /* CreateSecretView.swift */; };
 		5099A02723FE34FA0062B6F2 /* SmartCard.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5099A02623FE34FA0062B6F2 /* SmartCard.swift */; };
@@ -75,6 +75,7 @@
 		5099A07C240242BA0062B6F2 /* AgentTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5099A07B240242BA0062B6F2 /* AgentTests.swift */; };
 		5099A07E240242BA0062B6F2 /* SecretAgentKit.h in Headers */ = {isa = PBXBuildFile; fileRef = 5099A06E240242BA0062B6F2 /* SecretAgentKit.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		5099A08A240242C20062B6F2 /* SSHAgentProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5099A089240242C20062B6F2 /* SSHAgentProtocol.swift */; };
+		509FA3B625B53C49005E2535 /* ReleaseParsingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 509FA3B525B53C49005E2535 /* ReleaseParsingTests.swift */; };
 		50A3B79124026B7600D209EA /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 50A3B79024026B7600D209EA /* Assets.xcassets */; };
 		50A3B79424026B7600D209EA /* Preview Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 50A3B79324026B7600D209EA /* Preview Assets.xcassets */; };
 		50A3B79724026B7600D209EA /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 50A3B79524026B7600D209EA /* Main.storyboard */; };
@@ -281,7 +282,7 @@
 		508BF29425B4F140009EFB7E /* InternetAccessPolicy.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist; name = InternetAccessPolicy.plist; path = SecretAgent/InternetAccessPolicy.plist; sourceTree = SOURCE_ROOT; };
 		5091D2BB25183B830049FD9B /* ApplicationDirectoryController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ApplicationDirectoryController.swift; sourceTree = "<group>"; };
 		5091D31F2519D56D0049FD9B /* BriefTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = BriefTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
-		5091D3212519D56D0049FD9B /* BriefTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BriefTests.swift; sourceTree = "<group>"; };
+		5091D3212519D56D0049FD9B /* SemVerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SemVerTests.swift; sourceTree = "<group>"; };
 		5091D3232519D56D0049FD9B /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		5099A02323FD2AAA0062B6F2 /* CreateSecretView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CreateSecretView.swift; sourceTree = "<group>"; };
 		5099A02623FE34FA0062B6F2 /* SmartCard.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SmartCard.swift; sourceTree = "<group>"; };
@@ -295,6 +296,7 @@
 		5099A07B240242BA0062B6F2 /* AgentTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AgentTests.swift; sourceTree = "<group>"; };
 		5099A07D240242BA0062B6F2 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		5099A089240242C20062B6F2 /* SSHAgentProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SSHAgentProtocol.swift; sourceTree = "<group>"; };
+		509FA3B525B53C49005E2535 /* ReleaseParsingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReleaseParsingTests.swift; sourceTree = "<group>"; };
 		50A3B78A24026B7500D209EA /* SecretAgent.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = SecretAgent.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		50A3B79024026B7600D209EA /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		50A3B79324026B7600D209EA /* Preview Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = "Preview Assets.xcassets"; sourceTree = "<group>"; };
@@ -567,7 +569,8 @@
 		5091D3202519D56D0049FD9B /* BriefTests */ = {
 			isa = PBXGroup;
 			children = (
-				5091D3212519D56D0049FD9B /* BriefTests.swift */,
+				5091D3212519D56D0049FD9B /* SemVerTests.swift */,
+				509FA3B525B53C49005E2535 /* ReleaseParsingTests.swift */,
 				5091D3232519D56D0049FD9B /* Info.plist */,
 			);
 			path = BriefTests;
@@ -1077,7 +1080,8 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				5091D3222519D56D0049FD9B /* BriefTests.swift in Sources */,
+				509FA3B625B53C49005E2535 /* ReleaseParsingTests.swift in Sources */,
+				5091D3222519D56D0049FD9B /* SemVerTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};