diff --git a/src/nvim/os/win_defs.h b/src/nvim/os/win_defs.h
index d614582250..bfd431c9c6 100644
--- a/src/nvim/os/win_defs.h
+++ b/src/nvim/os/win_defs.h
@@ -28,7 +28,9 @@
 # endif
 #endif
 
+#ifdef _MSC_VER
 typedef SSIZE_T ssize_t;
+#endif
 
 #ifndef SSIZE_MAX
 # ifdef _WIN64