diff --git a/src/lib/nsas/nsas_messages.mes b/src/lib/nsas/nsas_messages.mes
index 0f32d09919..736c21ed62 100644
--- a/src/lib/nsas/nsas_messages.mes
+++ b/src/lib/nsas/nsas_messages.mes
@@ -12,10 +12,9 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-$PREFIX NSAS_
 $NAMESPACE isc::nsas
 
-% INVRESPSTR      queried for %1 but got invalid response
+% NSAS_INVRESPSTR      queried for %1 but got invalid response
 This message indicates an internal error in the nameserver address store
 component (NSAS) of the resolver.  The NSAS made a query for a RR for the
 specified nameserver but received an invalid response.  Either the success
@@ -23,36 +22,36 @@ function was called without a DNS message or the message was invalid on some
 way. (In the latter case, the error should have been picked up elsewhere in
 the processing logic, hence the raising of the error here.)
 
-% INVRESPTC       queried for %1 RR of type/class %2/%3, received response %4/%5
+% NSAS_INVRESPTC       queried for %1 RR of type/class %2/%3, received response %4/%5
 This message indicates an internal error in the nameserver address store
 component (NSAS) of the resolver.  The NSAS made a query for the given RR
 type and class, but instead received an answer with the given type and class.
 
-% LOOKUPCANCEL    lookup for zone %1 has been cancelled
+% NSAS_LOOKUPCANCEL    lookup for zone %1 has been cancelled
 A debug message, this is output when a NSAS (nameserver address store -
 part of the resolver) lookup for a zone has been cancelled.
 
-% LOOKUPZONE      searching NSAS for nameservers for zone %1
+% NSAS_LOOKUPZONE      searching NSAS for nameservers for zone %1
 A debug message, this is output when a call is made to the nameserver address
 store (part of the resolver) to obtain the nameservers for the specified zone.
 
-% NSADDR          asking resolver to obtain A and AAAA records for %1
+% NSAS_NSADDR          asking resolver to obtain A and AAAA records for %1
 A debug message, the NSAS (nameserver address store - part of the resolver) is
 making a callback into the resolver to retrieve the address records for the
 specified nameserver.
 
-% NSLKUPFAIL      failed to lookup any %1 for %2
+% NSAS_NSLKUPFAIL      failed to lookup any %1 for %2
 A debug message, the NSAS (nameserver address store - part of the resolver)
 has been unable to retrieve the specified resource record for the specified
 nameserver.  This is not necessarily a problem - the nameserver may be
 unreachable, in which case the NSAS will try other nameservers in the zone.
 
-% NSLKUPSUCC      found address %1 for %2
+% NSAS_NSLKUPSUCC      found address %1 for %2
 A debug message, the NSAS (nameserver address store - part of the resolver)
 has retrieved the given address for the specified nameserver through an
 external query.
 
-% SETRTT          reporting RTT for %1 as %2; new value is now %3
+% NSAS_SETRTT          reporting RTT for %1 as %2; new value is now %3
 A NSAS (nameserver address store - part of the resolver) debug message
 reporting the round-trip time (RTT) for a query made to the specified
 nameserver.  The RTT has been updated using the value given and the new RTT is