diff --git a/CMakeExternals/cpprestsdk.cmake b/CMakeExternals/cpprestsdk.cmake
index c815bbd32e..bb09838c5a 100644
--- a/CMakeExternals/cpprestsdk.cmake
+++ b/CMakeExternals/cpprestsdk.cmake
@@ -1,50 +1,51 @@
 set(proj cpprestsdk)
 set(proj_DEPENDENCIES Boost)
 
 find_package(ZLIB QUIET)
 
 if(NOT ZLIB_FOUND)
   list(APPEND proj_DEPENDENCIES ZLIB)
 endif()
 
 if(MITK_USE_${proj})
   set(${proj}_DEPENDS ${proj})
 
   if(DEFINED ${proj}_DIR AND NOT EXISTS ${${proj}_DIR})
     message(FATAL_ERROR "${proj}_DIR variable is defined but corresponds to non-existing directory!")
   endif()
 
   if(NOT DEFINED ${proj}_DIR)
     set(cmake_cache_args
       ${ep_common_cache_args}
       -DBUILD_SAMPLES:BOOL=OFF
       -DBUILD_TESTS:BOOL=OFF
+      -DWERROR:BOOL=OFF
     )
 
     if(OPENSSL_ROOT_DIR)
       list(APPEND cmake_cache_args
         -DOPENSSL_ROOT_DIR:PATH=${OPENSSL_ROOT_DIR}
       )
     endif()
 
     ExternalProject_Add(${proj}
       GIT_REPOSITORY https://github.com/Microsoft/cpprestsdk.git
       GIT_TAG v2.10.10
       SOURCE_SUBDIR Release
       CMAKE_ARGS ${ep_common_args}
       CMAKE_CACHE_ARGS ${cmake_cache_args}
       CMAKE_CACHE_DEFAULT_ARGS ${ep_common_cache_default_args}
     )
 
     ExternalProject_Add_Step(${proj} git-submodule
       COMMAND ${GIT_EXECUTABLE} submodule update --init -- Release/libs/websocketpp
       WORKING_DIRECTORY <SOURCE_DIR>
       DEPENDEES patch
       DEPENDERS configure
     )
 
     set(${proj}_DIR ${ep_prefix})
   else()
     mitkMacroEmptyExternalProject(${proj} "${proj_DEPENDENCIES}")
   endif()
 endif()