diff --git a/include/re_btrace.h b/include/re_btrace.h
index fef7f5b4e..aa3090ad5 100644
--- a/include/re_btrace.h
+++ b/include/re_btrace.h
@@ -25,7 +25,9 @@ static inline int btrace(struct btrace *bt)
 	return 0;
 }
 #elif defined(WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
 #include <windows.h>
 static inline int btrace(struct btrace *bt)
 {
diff --git a/src/btrace/btrace.c b/src/btrace/btrace.c
index e3ecc4de4..11d5d483f 100644
--- a/src/btrace/btrace.c
+++ b/src/btrace/btrace.c
@@ -8,7 +8,9 @@
 #include <unistd.h>
 #endif
 #ifdef WIN32
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
 #include <windows.h>
 #include <dbghelp.h>
 #endif