diff --git a/RELNOTES b/RELNOTES
index 2442a73f..de936e83 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -39,6 +39,9 @@ The system has only been tested on Linux, FreeBSD, and Solaris, and may not
 work on other platforms. Please report any problems and suggested fixes to
 <dhcp-users@isc.org>.
 
+			Changes since 4.2.0b2
+
+- Add declaration for variable in debug code in alloc.c.  [ISC-Bugs #21472]
 
 			Changes since 4.2.0b1
 
diff --git a/omapip/alloc.c b/omapip/alloc.c
index 9efb2b0a..e61be970 100644
--- a/omapip/alloc.c
+++ b/omapip/alloc.c
@@ -257,6 +257,7 @@ void dmalloc_dump_outstanding ()
 	struct dmalloc_preamble *dp;
 #if defined(DEBUG_MALLOC_POOL)
 	unsigned char *foo;
+	int i;
 #endif
 
 	if (!dmalloc_cutoff_point)