diff --git a/Plugins/org.mitk.gui.qt.xnat/CMakeLists.txt b/Plugins/org.mitk.gui.qt.xnat/CMakeLists.txt
index 3945fd909a..330e36df23 100644
--- a/Plugins/org.mitk.gui.qt.xnat/CMakeLists.txt
+++ b/Plugins/org.mitk.gui.qt.xnat/CMakeLists.txt
@@ -1,23 +1,23 @@
 project(org_mitk_gui_qt_xnat)
 
 find_package(OpenSSL)
 
 if( NOT OPENSSL_FOUND AND NOT SSL_EAY_RELEASE AND NOT LIB_EAY_RELEASE )
   message( "Could not find OpenSSL, XNAT will not work for HTTPS connections. Please set the SSL_EAY_RELEASE and LIB_EAY_RELEASE CMake variables to the respective libraries." )
 endif()
 
-if( WIN32 AND EXISTS ${SSL_EAY_RELEASE} AND EXISTS ${LIB_EAY_RELEASE} )
+if( WIN32 AND EXISTS "${SSL_EAY_RELEASE}" AND EXISTS "${LIB_EAY_RELEASE}" )
   configure_file( ${SSL_EAY_RELEASE} ${MITK_BINARY_DIR}/bin/Release/ COPYONLY )
   configure_file( ${LIB_EAY_RELEASE} ${MITK_BINARY_DIR}/bin/Release/ COPYONLY )
   configure_file( ${SSL_EAY_RELEASE} ${MITK_BINARY_DIR}/bin/Debug/ COPYONLY )
   configure_file( ${LIB_EAY_RELEASE} ${MITK_BINARY_DIR}/bin/Debug/ COPYONLY )
   MITK_INSTALL( FILES ${SSL_EAY_RELEASE})
   MITK_INSTALL( FILES ${LIB_EAY_RELEASE})
 endif()
 
 mitk_create_plugin(
   PACKAGE_DEPENDS Poco|Zip
   MODULE_DEPENDS MitkXNAT
   EXPORT_DIRECTIVE XNAT_EXPORT
   EXPORTED_INCLUDE_SUFFIXES src
 )