diff --git a/breeze6.spec b/breeze6.spec
index f2e0e6f..58e30f2 100644
--- a/breeze6.spec
+++ b/breeze6.spec
@@ -135,6 +135,7 @@ This package provides Breeze KWin decoration.
 # Otherwise, BuildRequires: cmake(Breeze) would pull some Qt5 and KF5 packages.
 %package devel
 Summary:          Information about breeze setup
+Conflicts:        breeze5-style < 6.0.0
 
 %description devel
 This package ships a CMake config file used to get information about Breeze.