diff --git a/imath.spec b/imath.spec
index a361360..5faf6ab 100644
--- a/imath.spec
+++ b/imath.spec
@@ -57,7 +57,7 @@ Requires:       python3-devel
 
 
 %build
-%cmake -DPYTHON=ON -DCMAKE_INSTALL_PREFIX=%{_usr}
+%cmake -DPYTHON=ON -DCMAKE_INSTALL_PREFIX=%{_prefix}
 %cmake_build
 
 # Generate man docs