diff --git a/mingw64-winpthreads.spec b/mingw64-winpthreads.spec
index feb1105..72b06ad 100644
--- a/mingw64-winpthreads.spec
+++ b/mingw64-winpthreads.spec
@@ -58,6 +58,7 @@ Group:          Development/Libraries/C and C++
 Requires:       mingw64-libwinpthread1 = %version
 Provides:       mingw64-unistd-pthread-devel
 Conflicts:      mingw64-headers-dummy-pthread, otherproviders(mingw64-unistd-pthread-devel)
+Obsoletes:      mingw64-headers-dummy-pthread
 
 %description devel
 mingw-w64's implementation of POSIX threads for Windows.