diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index 9f24761ce..bab2ac450 100755
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -104,7 +104,7 @@ IF(!UNBOUND_INCLUDE_DIR OR STATIC)
       libunbound
       PREFIX ${CMAKE_CURRENT_BINARY_DIR}/unbound
       URL ${CMAKE_CURRENT_SOURCE_DIR}/unbound/
-      CONFIGURE_COMMAND export USE_WINSOCK=1 && ${CMAKE_CURRENT_SOURCE_DIR}/unbound/configure --prefix=${CMAKE_FIND_ROOT_PATH} --build=${GCC_PREFIX} --host=${GCC_PREFIX} --disable-shared --enable-static --sysconfdir=${CMAKE_FIND_ROOT_PATH}/etc --localstatedir=${CMAKE_FIND_ROOT_PATH}/var --sbindir=${CMAKE_FIND_ROOT_PATH}/bin --disable-gost --disable-rpath --with-libevent=no --with-libexpat=${CMAKE_FIND_ROOT_PATH} --without-pyunbound --without-pythonmodule --with-ssl=${CMAKE_FIND_ROOT_PATH} --without-pthreads --with-libunbound-only
+      CONFIGURE_COMMAND COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/unbound/configure USE_WINSOCK=1 --prefix=${CMAKE_FIND_ROOT_PATH} --build=${GCC_PREFIX} --host=${GCC_PREFIX} --disable-shared --enable-static --sysconfdir=${CMAKE_FIND_ROOT_PATH}/etc --localstatedir=${CMAKE_FIND_ROOT_PATH}/var --sbindir=${CMAKE_FIND_ROOT_PATH}/bin --disable-gost --disable-rpath --with-libevent=no --with-libexpat=${CMAKE_FIND_ROOT_PATH} --without-pyunbound --without-pythonmodule --with-ssl=${CMAKE_FIND_ROOT_PATH} --without-pthreads --with-libunbound-only
       BUILD_COMMAND $(MAKE)
       UPDATE_COMMAND ""
       PATCH_COMMAND ""