diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index 352336fc..5e6f7bbf 100755
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -103,7 +103,7 @@ set( PKGCONFIG_REQUIRES fmt )
 
 find_package( TIRPC QUIET )
 if( TIRPC_FOUND )
-    set( PKGCONFIG_REQUIRES libtirpc )
+    set( PKGCONFIG_REQUIRES "${PKGCONFIG_REQUIRES} libtirpc" )
 endif()
 
 if( ENABLE_CAPNP )