diff --git a/SHSTKMacros.cmake b/SHSTKMacros.cmake
index b960115..01bbd6d 100644
--- a/SHSTKMacros.cmake
+++ b/SHSTKMacros.cmake
@@ -313,7 +313,7 @@ macro(shstk_find_header name filename add_find_info)
 		get_filename_component(_inc ${${name}_H_INCLUDE} PATH)
 		set(${name}_INCLUDES "${_inc}" CACHE STRING "")
 		include(CheckSymbolExists)
-		check_symbol_exists(${name}_VERSION_NAME "${${name}_H_INCLUDE}" _${name}_version_found)
+		check_symbol_exists(${${name}_uppercase}_VERSION_NAME "${${name}_H_INCLUDE}" _${name}_version_found)
 		if (_${name}_version_found)
 			file(STRINGS "${${name}_H_INCLUDE}" _version REGEX "^[ \t]*#define[ \t]+${${name}_uppercase}_VERSION_NAME+[ \t]+.*$")
 			string(REGEX MATCH "\".*\"" _version ${_version})