diff --git a/Sources/rswift/App.swift b/Sources/rswift/App.swift
index bb5be219..749d4837 100644
--- a/Sources/rswift/App.swift
+++ b/Sources/rswift/App.swift
@@ -88,7 +88,7 @@ extension App {
             let sourceTreeURLs = SourceTreeURLs(
                 builtProductsDirURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.builtProductsDir] ?? EnvironmentKeys.builtProductsDir),
                 developerDirURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.developerDir] ?? EnvironmentKeys.developerDir),
-                sourceRootURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.sourceRoot] ?? ""),
+                sourceRootURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.sourceRoot] ?? "."),
                 sdkRootURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.sdkRoot] ?? EnvironmentKeys.sdkRoot),
                 platformURL: URL(fileURLWithPath: processInfo.environment[EnvironmentKeys.platformDir] ?? EnvironmentKeys.platformDir)
             )