diff --git a/libshvchainpack/c/include/shv/chainpack/compat.h b/libshvchainpack/c/include/shv/chainpack/compat.h
index 6608846e..6da358aa 100644
--- a/libshvchainpack/c/include/shv/chainpack/compat.h
+++ b/libshvchainpack/c/include/shv/chainpack/compat.h
@@ -1,11 +1,5 @@
 #pragma once
-#ifdef __has_include
-	#if __has_include(<unistd.h>)
-		#include <unistd.h>
-	#endif
-#endif
-
-#ifndef __ssize_t_defined
+#ifdef _MSC_VER
 #include <stdint.h>
 typedef intmax_t ssize_t;
 #endif