diff --git a/net-snmp-5.5-sysobjectid-truncation.patch b/net-snmp-5.5-sysobjectid-truncation.patch
new file mode 100644
index 0000000..9af2837
--- /dev/null
+++ b/net-snmp-5.5-sysobjectid-truncation.patch
@@ -0,0 +1,51 @@
+640848:  snmpd always returns an incorrect sysObjectID of ".1.3" or ".0.1"
+
+Source: upstream, SVN rev. 19322
+
+Index: net-snmp/agent/mibgroup/mibII/system_mib.c
+===================================================================
+--- net-snmp/agent/mibgroup/mibII/system_mib.c	(revision 17596)
++++ net-snmp/agent/mibgroup/mibII/system_mib.c	(working copy)
+@@ -60,7 +57,7 @@
+ static char     sysName[SYS_STRING_LEN] = NETSNMP_SYS_NAME;
+ static char     sysLocation[SYS_STRING_LEN] = NETSNMP_SYS_LOC;
+ static oid      sysObjectID[MAX_OID_LEN];
+-static size_t   sysObjectIDLength;
++static size_t sysObjectIDByteLength;
+ 
+ extern oid      version_sysoid[];
+ extern int      version_sysoid_len;
+@@ -171,12 +168,11 @@
+ static void
+ system_parse_config_sysObjectID(const char *token, char *cptr)
+ {
+-    sysObjectIDLength = MAX_OID_LEN;
++    size_t sysObjectIDLength = MAX_OID_LEN;
+     if (!read_objid(cptr, sysObjectID, &sysObjectIDLength)) {
+ 	netsnmp_config_error("sysobjectid token not a parsable OID:\n\t%s",
+ 			     cptr);
+         memcpy(sysObjectID, version_sysoid, version_sysoid_len * sizeof(oid));
+-        sysObjectIDLength = version_sysoid_len;
+     }
+ }
+ 
+@@ -318,7 +314,7 @@
+ 
+     /* default sysObjectID */
+     memcpy(sysObjectID, version_sysoid, version_sysoid_len * sizeof(oid));
+-    sysObjectIDLength = version_sysoid_len;
++    sysObjectIDByteLength = version_sysoid_len * sizeof(oid);
+ 
+     {
+         const oid sysDescr_oid[] = { 1, 3, 6, 1, 2, 1, 1, 1 };
+@@ -340,8 +336,8 @@
+                 HANDLER_CAN_RONLY),
+             netsnmp_init_watcher_info6(
+ 		&sysObjectID_winfo, sysObjectID, 0, ASN_OBJECT_ID,
+-		WATCHER_MAX_SIZE | WATCHER_SIZE_IS_PTR,
+-		MAX_OID_LEN, &sysObjectIDLength));
++                WATCHER_MAX_SIZE | WATCHER_SIZE_IS_PTR,
++                MAX_OID_LEN, &sysObjectIDByteLength));
+     }
+     {
+         const oid sysUpTime_oid[] = { 1, 3, 6, 1, 2, 1, 1, 3 };
diff --git a/net-snmp.spec b/net-snmp.spec
index f608f9c..b183308 100644
--- a/net-snmp.spec
+++ b/net-snmp.spec
@@ -11,7 +11,7 @@
 Summary: A collection of SNMP protocol tools and libraries
 Name: net-snmp
 Version: 5.5
-Release: 20%{?dist}
+Release: 21%{?dist}
 Epoch: 1
 
 License: BSD
@@ -38,6 +38,7 @@ Patch9: net-snmp-5.5-include-struct.patch
 Patch10: net-snmp-5.5-mktemp-size.patch
 Patch11: net-snmp-5.5-apsl-copying.patch
 Patch12: net-snmp-5.5-perl-linking.patch
+Patch13: net-snmp-5.5-sysobjectid-truncation.patch
 
 Requires(post): chkconfig
 Requires(preun): chkconfig
@@ -174,6 +175,7 @@ Net-SNMP toolkit library.
 %patch10 -p1 -b .mktemp-size
 %patch11 -p1 -b .apsl
 %patch12 -p1 -b .perl-linking
+%patch13 -p1 -b .sysobjectid-truncation
 
 %build
 MIBS="host agentx smux \
@@ -422,6 +424,9 @@ rm -rf ${RPM_BUILD_ROOT}
 %{_datadir}/snmp/mibs/*
 
 %changelog
+* Mon Oct 11 2010 Jan Safranek <jsafrane@redhat.com> - 1:5.5-21
+- fixed truncation of sysObjectID (#640848)
+
 * Thu Aug 19 2010 Jan Safranek <jsafrane@redhat.com> - 1:5.5-20
 - Remove rpath from net-snmp-config output (#554747)