diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 2119943..7e7fa86 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -18,6 +18,9 @@ include_directories ("${gflags_BINARY_DIR}/include/gflags")
 
 if (BUILD_SHARED_LIBS)
   set (type shared)
+  if (GFLAGS_IS_A_DLL)
+    add_definitions(-DGFLAGS_IS_A_DLL)
+  endif ()
 else ()
   set (type static)
 endif ()