diff --git a/Foundation/Process.swift b/Foundation/Process.swift
index c89a244a92..2b20399320 100644
--- a/Foundation/Process.swift
+++ b/Foundation/Process.swift
@@ -386,6 +386,11 @@ open class Process: NSObject {
         // Dispatch the manager thread if it isn't already running
         Process.setup()
 
+        // Check that the process isnt run more than once
+        guard hasStarted == false && hasFinished == false else {
+            throw NSError(domain: NSCocoaErrorDomain, code: NSExecutableLoadError)
+        }
+
         // Ensure that the launch path is set
         guard let launchPath = self.executableURL?.path else {
             throw NSError(domain: NSCocoaErrorDomain, code: NSFileNoSuchFileError)
diff --git a/TestFoundation/TestProcess.swift b/TestFoundation/TestProcess.swift
index 935a7c3735..12750d1155 100644
--- a/TestFoundation/TestProcess.swift
+++ b/TestFoundation/TestProcess.swift
@@ -319,15 +319,26 @@ class TestProcess : XCTestCase {
         XCTAssertEqual(fm.currentDirectoryPath, cwd)
 
         do {
+            // Check running the process twice throws an error.
             let process = Process()
             process.executableURL = xdgTestHelperURL()
             process.arguments = ["--exit", "0"]
-            process.currentDirectoryURL = URL(fileURLWithPath: "/.../_no_such_directory", isDirectory: true)
-            try process.run()
-            XCTFail("Executed \(xdgTestHelperURL().path) with invalid currentDirectoryURL")
-            process.terminate()
+            XCTAssertNoThrow(try process.run())
             process.waitUntilExit()
-        } catch {
+            XCTAssertThrowsError(try process.run()) {
+                let nserror = ($0 as! NSError)
+                XCTAssertEqual(nserror.domain, NSCocoaErrorDomain)
+                let code = CocoaError(_nsError: nserror).code
+                XCTAssertEqual(code, .executableLoad)
+            }
+        }
+
+        do {
+            let process = Process()
+            process.executableURL = xdgTestHelperURL()
+            process.arguments = ["--exit", "0"]
+            process.currentDirectoryURL = URL(fileURLWithPath: "/.../_no_such_directory", isDirectory: true)
+            XCTAssertThrowsError(try process.run())
         }
         XCTAssertEqual(fm.currentDirectoryPath, cwd)
 
@@ -336,11 +347,7 @@ class TestProcess : XCTestCase {
             process.executableURL = URL(fileURLWithPath: "/..", isDirectory: false)
             process.arguments = []
             process.currentDirectoryURL = URL(fileURLWithPath: NSTemporaryDirectory())
-            try process.run()
-            XCTFail("Somehow executed a directory!")
-            process.terminate()
-            process.waitUntilExit()
-        } catch {
+            XCTAssertThrowsError(try process.run())
         }
         XCTAssertEqual(fm.currentDirectoryPath, cwd)
         fm.changeCurrentDirectoryPath(cwd)