diff --git a/library/platform_util.c b/library/platform_util.c
index d0abc17..8141dd8 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -44,7 +44,7 @@
 #endif
 
 // Detect platforms known to support explicit_bzero()
-#if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25)
+#if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25) && defined(__unix__)
 #define MBEDTLS_PLATFORM_HAS_EXPLICIT_BZERO 1
 #endif
 #if defined(__FreeBSD__) && __FreeBSD_version >= 1100037