diff --git a/Modules/FindOpenSSL.cmake b/Modules/FindOpenSSL.cmake
index 426d00dcec..10282a042d 100644
--- a/Modules/FindOpenSSL.cmake
+++ b/Modules/FindOpenSSL.cmake
@@ -230,7 +230,7 @@ else()
   set(_OPENSSL_FIND_PATH_SUFFIX "include")
 endif()
 
-if ((DEFINED OPENSSL_ROOT_DIR) OR (DEFINED ENV{OPENSSL_ROOT_DIR}))
+if (OPENSSL_ROOT_DIR OR NOT "$ENV{OPENSSL_ROOT_DIR}" STREQUAL "")
   set(_OPENSSL_ROOT_HINTS HINTS ${OPENSSL_ROOT_DIR} ENV OPENSSL_ROOT_DIR)
   set(_OPENSSL_ROOT_PATHS NO_DEFAULT_PATH)
 elseif (MSVC)