diff --git a/cmake/Modules/GeneratePkgConfig.cmake b/cmake/Modules/GeneratePkgConfig.cmake
index 3c4520b22..0a2f18a56 100644
--- a/cmake/Modules/GeneratePkgConfig.cmake
+++ b/cmake/Modules/GeneratePkgConfig.cmake
@@ -30,6 +30,7 @@ endfunction()
 function(_get_target_property_merging_configs _var_name _target_name _propert_name)
 	get_target_property(vals ${_target_name} ${_propert_name})
 	if (NOT vals)
+		set(vals "")
 		if (CMAKE_BUILD_TYPE)
 			list(APPEND configs ${CMAKE_BUILD_TYPE})
 		elseif()