diff --git a/CHANGES b/CHANGES
index 2c68faf94f..caf2834d83 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+2174.	[bug]		I/O errors should always be fatal when reading
+			master files. [RT #16825]
+
 2173.	[port]		win32: When compiling with MSVS 2005 SP1 we also
 			need to ship Microsoft.VC80.MFCLOC.
 
diff --git a/lib/dns/master.c b/lib/dns/master.c
index a3f62902c0..cf07ebc5f0 100644
--- a/lib/dns/master.c
+++ b/lib/dns/master.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: master.c,v 1.161 2006/12/07 23:57:59 marka Exp $ */
+/* $Id: master.c,v 1.162 2007/05/02 04:06:24 marka Exp $ */
 
 /*! \file */
 
@@ -276,7 +276,8 @@ loadctx_destroy(dns_loadctx_t *lctx);
 
 #define MANYERRS(lctx, result) \
 		((result != ISC_R_SUCCESS) && \
-		((lctx)->options & DNS_MASTER_MANYERRORS) != 0)
+		 (result != ISC_R_IOERROR) && \
+		 ((lctx)->options & DNS_MASTER_MANYERRORS) != 0)
 
 #define SETRESULT(lctx, r) \
 		do { \