diff --git a/src/gallium/auxiliary/util/u_debug_refcnt.c b/src/gallium/auxiliary/util/u_debug_refcnt.c
index f849e59cb3e..a25234b46cf 100644
--- a/src/gallium/auxiliary/util/u_debug_refcnt.c
+++ b/src/gallium/auxiliary/util/u_debug_refcnt.c
@@ -53,7 +53,11 @@ static FILE *stream;
 /* TODO: maybe move this serial machinery to a stand-alone module and
  * expose it?
  */
+#ifdef PIPE_OS_WINDOWS
+static mtx_t serials_mutex;
+#else
 static mtx_t serials_mutex = _MTX_INITIALIZER_NP;
+#endif
 
 static struct hash_table *serials_hash;
 static unsigned serials_last;
diff --git a/src/gallium/auxiliary/util/u_debug_symbol.c b/src/gallium/auxiliary/util/u_debug_symbol.c
index 334803d008e..4bbed585d81 100644
--- a/src/gallium/auxiliary/util/u_debug_symbol.c
+++ b/src/gallium/auxiliary/util/u_debug_symbol.c
@@ -271,7 +271,11 @@ debug_symbol_print(const void *addr)
 }
 
 struct hash_table* symbols_hash;
+#ifdef PIPE_OS_WINDOWS
+static mtx_t symbols_mutex;
+#else
 static mtx_t symbols_mutex = _MTX_INITIALIZER_NP;
+#endif
 
 const char*
 debug_symbol_name_cached(const void *addr)