diff --git a/include/json/version.h b/include/json/version.h
index e931d03..bf7a6a3 100644
--- a/include/json/version.h
+++ b/include/json/version.h
@@ -18,10 +18,11 @@
   ((JSONCPP_VERSION_MAJOR << 24) | (JSONCPP_VERSION_MINOR << 16) |             \
    (JSONCPP_VERSION_PATCH << 8))
 
-#ifdef JSONCPP_USING_SECURE_MEMORY
-#undef JSONCPP_USING_SECURE_MEMORY
+#if defined(JSONCPP_USE_SECURE_MEMORY)
+  #define JSONCPP_USING_SECURE_MEMORY 1
+#else
+  #define JSONCPP_USING_SECURE_MEMORY 0
 #endif
-#define JSONCPP_USING_SECURE_MEMORY 0
 // If non-zero, the library zeroes any memory that it has allocated before
 // it frees its memory.