diff --git a/CMake/OpenIGTLinkCMakeTests.cmake b/CMake/OpenIGTLinkCMakeTests.cmake
index 54447444..a42159ea 100644
--- a/CMake/OpenIGTLinkCMakeTests.cmake
+++ b/CMake/OpenIGTLinkCMakeTests.cmake
@@ -5,7 +5,7 @@ INCLUDE(CheckFunctionExists)
 
 CHECK_LIBRARY_EXISTS("socket" getsockname "" OpenIGTLink_HAVE_LIBSOCKET)
 
-IF("OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T" MATCHES "^OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T$")
+IF(NOT DEFINED "OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T")
   IF(OpenIGTLink_HAVE_LIBSOCKET)
     SET(OpenIGTLink_GETSOCKNAME_LIBS "socket")
   ELSE(OpenIGTLink_HAVE_LIBSOCKET)
@@ -32,7 +32,7 @@ IF("OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T" MATCHES "^OpenIGTLink_HAVE_GETS
       "failed with the following output:\n"
       "${OUTPUT}\n" APPEND)
   ENDIF(OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T)
-ENDIF("OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T" MATCHES "^OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T$")
+ENDIF(NOT DEFINED "OpenIGTLink_HAVE_GETSOCKNAME_WITH_SOCKLEN_T")
 
 
 # e.g. Mac OS X Snow Leopard does not have strnlen().