diff --git a/swift/Package.swift b/swift/Package.swift
index 3430427..01ce9da 100644
--- a/swift/Package.swift
+++ b/swift/Package.swift
@@ -1,4 +1,5 @@
 // swift-tools-version: 5.9
+import Foundation
 import PackageDescription
 
 // Wraps the Zig usage core for native hosts. Build the library first:
@@ -9,6 +10,15 @@ import PackageDescription
 // The core does no I/O: it builds the requests and parses the responses, and UsageDriver feeds it
 // through URLSession. That is the whole point of the split — TLS, proxies and HTTP/2 stay with the
 // host, and the rules stay in one place shared with the CLI.
+//
+// The path to libusage.a is absolute because this package is also consumed as a dependency: a
+// relative path would be resolved against whoever is building, not against this directory.
+let packageRoot = URL(fileURLWithPath: #filePath)
+	.deletingLastPathComponent() // the manifest
+	.deletingLastPathComponent() // swift/
+	.path
+let staticLibrary = "\(packageRoot)/zig-out/lib/libusage.a"
+
 let package = Package(
 	name: "UsageCore",
 	platforms: [.macOS(.v13)],
@@ -22,13 +32,13 @@ let package = Package(
 			name: "UsageCore",
 			dependencies: ["CUsage"],
 			path: "Sources/UsageCore",
-			linkerSettings: [.unsafeFlags(["../zig-out/lib/libusage.a"])]
+			linkerSettings: [.unsafeFlags([staticLibrary])]
 		),
 		.executableTarget(
 			name: "UsageSmoke",
 			dependencies: ["UsageCore"],
 			path: "Sources/UsageSmoke",
-			linkerSettings: [.unsafeFlags(["../zig-out/lib/libusage.a"])]
+			linkerSettings: [.unsafeFlags([staticLibrary])]
 		),
 	]
 )