diff --git a/src/epics/util/lib/Parser3.pm b/src/epics/util/lib/Parser3.pm
index ebaa59d72baa23302d91b1d789fc98bcca74fac1..e854a32a82266819f659b224ed1d42ed40cfb472 100644
--- a/src/epics/util/lib/Parser3.pm
+++ b/src/epics/util/lib/Parser3.pm
@@ -643,7 +643,7 @@ sub node_processing {
 		return 1; # Do not call this function on leaves, we already did that
 	} elsif ($block_type eq "Reference") {
                 if ($source_block =~ /cdsIPCx/) {
-                   if ($block_name !~ /[CGHKLMSX]\d\:/) {
+                   if ($block_name !~ /[A-Z]\d\:/) {
                       die "***ERROR: Signal name of IPCx module must include IFO: $block_name\n";
                    }
                 }