diff --git a/src/backend/utils/mb/Unicode/UCS_to_BIG5.pl b/src/backend/utils/mb/Unicode/UCS_to_BIG5.pl
index 0412723..822ab28 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_BIG5.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_BIG5.pl
@@ -25,7 +25,7 @@
 #		 # and Unicode name (not used in this script)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_EUC_CN.pl b/src/backend/utils/mb/Unicode/UCS_to_EUC_CN.pl
index 76ad502..a933c12 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_EUC_CN.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_EUC_CN.pl
@@ -14,7 +14,7 @@
 # and the "b" field is the hex byte sequence for GB18030
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_EUC_JIS_2004.pl b/src/backend/utils/mb/Unicode/UCS_to_EUC_JIS_2004.pl
index a0f61e7..38c0b2a 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_EUC_JIS_2004.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_EUC_JIS_2004.pl
@@ -8,7 +8,7 @@
 # "euc-jis-2004-std.txt" (http://x0213.org)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_EUC_JP.pl b/src/backend/utils/mb/Unicode/UCS_to_EUC_JP.pl
index 7f2d228..5ac3542 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_EUC_JP.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_EUC_JP.pl
@@ -12,7 +12,7 @@
 # organization's ftp site.
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_EUC_KR.pl b/src/backend/utils/mb/Unicode/UCS_to_EUC_KR.pl
index 040c5fe..d17d777 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_EUC_KR.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_EUC_KR.pl
@@ -17,7 +17,7 @@
 #		 # and Unicode name (not used in this script)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_EUC_TW.pl b/src/backend/utils/mb/Unicode/UCS_to_EUC_TW.pl
index 046a8a3..603edc4 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_EUC_TW.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_EUC_TW.pl
@@ -18,7 +18,7 @@
 #		 # and Unicode name (not used in this script)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl b/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
index 61e31af..e20b4a8 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
@@ -14,7 +14,7 @@
 # and the "b" field is the hex byte sequence for GB18030
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_JOHAB.pl b/src/backend/utils/mb/Unicode/UCS_to_JOHAB.pl
index b60858e..2dc9fb3 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_JOHAB.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_JOHAB.pl
@@ -16,7 +16,7 @@
 #		 # and Unicode name (not used in this script)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_SHIFT_JIS_2004.pl b/src/backend/utils/mb/Unicode/UCS_to_SHIFT_JIS_2004.pl
index 2e66e63..51ab6a1 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_SHIFT_JIS_2004.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_SHIFT_JIS_2004.pl
@@ -8,7 +8,7 @@
 # "sjis-0213-2004-std.txt" (http://x0213.org)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 # first generate UTF-8 --> SHIFT_JIS_2004 table
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_SJIS.pl b/src/backend/utils/mb/Unicode/UCS_to_SJIS.pl
index 9a1cc52..ffeb65f 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_SJIS.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_SJIS.pl
@@ -11,7 +11,7 @@
 # ftp site.
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_UHC.pl b/src/backend/utils/mb/Unicode/UCS_to_UHC.pl
index d297d9a..2905b95 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_UHC.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_UHC.pl
@@ -14,7 +14,7 @@
 # and the "b" field is the hex byte sequence for UHC
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/UCS_to_most.pl b/src/backend/utils/mb/Unicode/UCS_to_most.pl
index 9503076..572c232 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_most.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_most.pl
@@ -16,7 +16,7 @@
 #		 # and Unicode name (not used in this script)
 
 use strict;
-require "convutils.pm";
+require convutils;
 
 my $this_script = $0;
 
diff --git a/src/backend/utils/mb/Unicode/make_mapchecker.pl b/src/backend/utils/mb/Unicode/make_mapchecker.pl
index c96457c..6de0b3f 100755
--- a/src/backend/utils/mb/Unicode/make_mapchecker.pl
+++ b/src/backend/utils/mb/Unicode/make_mapchecker.pl
@@ -22,7 +22,7 @@ foreach my $rmap (@radixmaps)
 
 # Generate sanity checker source
 my $out;
-open($out, ">map_checker.h")
+open($out, '>', "map_checker.h")
   || die "cannot open file to write: map_checker.h";
 foreach my $i (sort @radixmaps)
 {
@@ -30,7 +30,7 @@ foreach my $i (sort @radixmaps)
 	print $out "#include \"$plainmaps{$i}\"\n";
 }
 
-my @mapnames = map { s/\.map//; $_ } values %plainmaps;
+my @mapnames = map { my $m = $_; $m =~ s/\.map//; $m } values %plainmaps;
 
 print $out <<'EOF';