diff --git a/App/tools/expandDBD.pl b/App/tools/expandDBD.pl
index d95df85..05aafeb 100755
--- a/App/tools/expandDBD.pl
+++ b/App/tools/expandDBD.pl
@@ -7,7 +7,7 @@ use 5.010;
 use File::Basename qw/basename/;
 use File::Spec::Functions qw/catfile/;
 
-my $epicsversion = 3.14;
+my $epicsversion = 0x030E0000; # 3.14
 my $quiet = 0;
 my @searchpath = ();
 my %filesDone = ();
@@ -15,13 +15,30 @@ my @filesInput = ();
 
 while (@ARGV) {
     my $arg = shift @ARGV;
-    if ($arg =~ /^-\d/) { $epicsversion = substr($arg, 1); }
+    if ($arg =~ /^-(\d+(.\d+){0,3})$/) { $epicsversion = parseVersion($1); }
     elsif ($arg eq "-q") { $quiet = 1; }
     elsif ($arg =~ /^-I$/) { push @searchpath, shift @ARGV; }
     elsif ($arg =~ /^-I(.*)$/) { push @searchpath, $1; }
     else { push @filesInput, $arg; }
 }
 
+##
+## Convert version string of version.revision.modification.patch format
+## to integer format 0Xvvrrmmpp (in hexadecimal)
+##   3.14.12.8 -> 0x030E0C08
+##   7.0.3 -> 0x07000300
+## This requires all parts of version number are in range 0-255,
+## which is true for EPICS base version number.
+##
+sub parseVersion {
+    my @vi = split(/\./, shift); # version integers list
+    my $vh = 0; # hexadecimal version
+    foreach my $i (0..$#vi) {
+        $vh |= $vi[$i] << (8 * (3-$i));
+    }
+    return $vh;
+}
+
 ##
 ## Search given dbd file from @searchpath list.
 ## If it is not found, return the file name as it is.
@@ -87,10 +104,10 @@ sub scanfile {
             return 0 unless scanfile($1, $name, $n);
         }
         elsif (/(registrar|variable|function)[ \t]*\([ \t]*"?([a-zA-Z0-9_]+)"?[ \t]*\)/) {
-            say "$1($2)" if $epicsversion gt 3.13;
+            say "$1($2)" if $epicsversion > 0x030D0000; # 3.13
         }
         elsif (/variable[ \t]*\([ \t]*"?([a-zA-Z0-9_]+)"?[ \t]*,[ \t]*"?([a-zA-Z0-9_]+)"?[ \t]*\)/) {
-            say "variable($1,$2)" if $epicsversion gt 3.13;
+            say "variable($1,$2)" if $epicsversion > 0x030D0000; # 3.13
         }
         else {
             say;