diff --git a/defines.h b/defines.h
index b7dd1d9cf..fa0ccba7c 100644
--- a/defines.h
+++ b/defines.h
@@ -822,14 +822,6 @@ struct winsize {
 # define SSH_IOBUFSZ 8192
 #endif
 
-#ifndef _NSIG
-# ifdef NSIG
-#  define _NSIG NSIG
-# else
-#  define _NSIG 128
-# endif
-#endif
-
 /*
  * Platforms that have arc4random_uniform() and not arc4random_stir()
  * shouldn't need the latter.
diff --git a/openbsd-compat/readpassphrase.c b/openbsd-compat/readpassphrase.c
index 62b6d0d84..d63cdf2f0 100644
--- a/openbsd-compat/readpassphrase.c
+++ b/openbsd-compat/readpassphrase.c
@@ -46,6 +46,14 @@
 #  define _POSIX_VDISABLE       VDISABLE
 #endif
 
+#ifndef _NSIG
+# ifdef NSIG
+#  define _NSIG NSIG
+# else
+#  define _NSIG 128
+# endif
+#endif
+
 static volatile sig_atomic_t signo[_NSIG];
 
 static void handler(int);