diff --git a/eigen3.spec b/eigen3.spec
index 11b1de3..5dab1fd 100644
--- a/eigen3.spec
+++ b/eigen3.spec
@@ -68,7 +68,7 @@ Developer documentation for Eigen.
 
 
 %prep
-%autosetup -p1
+%autosetup -p1 -n eigen-%{version}
 
 
 %build