diff --git a/lib/db/dbmi_base/dirent.c b/lib/db/dbmi_base/dirent.c
index b306e13c4d7..09bdc257c2e 100644
--- a/lib/db/dbmi_base/dirent.c
+++ b/lib/db/dbmi_base/dirent.c
@@ -21,8 +21,8 @@
 #include <grass/dbmi.h>
 
 /* NOTE: these should come from <unistd.h> or from <sys/file.h> */
-#ifndef R_OK
 #if !defined(HAVE_UNISTD_H)
+#ifndef R_OK
 #define R_OK 4
 #endif
 #ifndef W_OK