diff --git a/nimble.nimble b/nimble.nimble
index 7b3917a..cf6b4d4 100644
--- a/nimble.nimble
+++ b/nimble.nimble
@@ -1,4 +1,4 @@
-when dirExists("src"):
+when fileExists("src/nimblepkg/common.nim"):
   # In the git repository the Nimble sources are in a ``src`` directory.
   import src/nimblepkg/common
 else: