diff --git a/app/pdb/color-cmds.c b/app/pdb/color-cmds.c
index b3e8ce088e..bfa24a4822 100644
--- a/app/pdb/color-cmds.c
+++ b/app/pdb/color-cmds.c
@@ -1116,13 +1116,13 @@ register_color_procs (GimpPDB *pdb)
                                gimp_param_spec_int32 ("start-range",
                                                       "start range",
                                                       "Start of the intensity measurement range",
-                                                      0, 256, 0,
+                                                      0, 255, 0,
                                                       GIMP_PARAM_READWRITE));
   gimp_procedure_add_argument (procedure,
                                gimp_param_spec_int32 ("end-range",
                                                       "end range",
                                                       "End of the intensity measurement range",
-                                                      0, 256, 0,
+                                                      0, 255, 0,
                                                       GIMP_PARAM_READWRITE));
   gimp_procedure_add_return_value (procedure,
                                    g_param_spec_double ("mean",
diff --git a/tools/pdbgen/app.pl b/tools/pdbgen/app.pl
index f867449c94..2a143f1641 100644
--- a/tools/pdbgen/app.pl
+++ b/tools/pdbgen/app.pl
@@ -324,8 +324,18 @@ g_param_spec_double ("$name",
 CODE
     }
     elsif ($pdbtype eq 'int32') {
-	$min = defined $typeinfo[0] ? $typeinfo[0] : G_MININT32;
-	$max = defined $typeinfo[2] ? $typeinfo[2] : G_MAXINT32;
+	if (defined $typeinfo[0]) {
+	    $min = ($typeinfo[1] eq '<') ? ($typeinfo[0] + 1) : $typeinfo[0];
+	}
+	else {
+	    $min = G_MININT32;
+	}
+	if (defined $typeinfo[2]) {
+	    $max = ($typeinfo[3] eq '<') ? ($typeinfo[2] - 1) : $typeinfo[2];
+	}
+	else {
+	    $max = G_MAXINT32;
+	}
 	$default = exists $arg->{default} ? $arg->{default} : defined $typeinfo[0] ? $typeinfo[0] : 0;
 	$pspec = <<CODE;
 gimp_param_spec_int32 ("$name",
@@ -336,8 +346,18 @@ gimp_param_spec_int32 ("$name",
 CODE
     }
     elsif ($pdbtype eq 'int16') {
-	$min = defined $typeinfo[0] ? $typeinfo[0] : G_MININT16;
-	$max = defined $typeinfo[2] ? $typeinfo[2] : G_MAXINT16;
+	if (defined $typeinfo[0]) {
+	    $min = ($typeinfo[1] eq '<') ? ($typeinfo[0] + 1) : $typeinfo[0];
+	}
+	else {
+	    $min = G_MININT16;
+	}
+	if (defined $typeinfo[2]) {
+	    $max = ($typeinfo[3] eq '<') ? ($typeinfo[2] - 1) : $typeinfo[2];
+	}
+	else {
+	    $max = G_MAXINT16;
+	}
 	$default = exists $arg->{default} ? $arg->{default} : defined $typeinfo[0] ? $typeinfo[0] : 0;
 	$pspec = <<CODE;
 gimp_param_spec_int16 ("$name",
@@ -348,8 +368,18 @@ gimp_param_spec_int16 ("$name",
 CODE
     }
     elsif ($pdbtype eq 'int8') {
-	$min = defined $typeinfo[0] ? $typeinfo[0] : 0;
-	$max = defined $typeinfo[2] ? $typeinfo[2] : G_MAXUINT8;
+	if (defined $typeinfo[0]) {
+	    $min = ($typeinfo[1] eq '<') ? ($typeinfo[0] + 1) : $typeinfo[0];
+	}
+	else {
+	    $min = 0;
+	}
+	if (defined $typeinfo[2]) {
+	    $max = ($typeinfo[3] eq '<') ? ($typeinfo[2] - 1) : $typeinfo[2];
+	}
+	else {
+	    $max = G_MAXUINT8;
+	}
 	$default = exists $arg->{default} ? $arg->{default} : defined $typeinfo[0] ? $typeinfo[0] : 0;
 	$pspec = <<CODE;
 gimp_param_spec_int8 ("$name",
diff --git a/tools/pdbgen/pdb.pl b/tools/pdbgen/pdb.pl
index 4ca1904361..4058302fe3 100644
--- a/tools/pdbgen/pdb.pl
+++ b/tools/pdbgen/pdb.pl
@@ -228,20 +228,6 @@ package Gimp::CodeGen::pdb;
 
 # Split out the parts of an arg constraint
 sub arg_parse {
-    my %premap = (
-	'<'  => '<=',
-	'>'  => '>=',
-	'<=' => '<',
-	'>=' => '>'
-    );
-
-    my %postmap = (
-	'<'  => '>=',
-	'>'  => '<=',
-	'<=' => '>',
-	'>=' => '<'
-    );
-
     my $arg = shift;
 
     if ($arg =~ /^enum (\w+)(.*)/) {
@@ -264,7 +250,7 @@ sub arg_parse {
 		     \s* (\w+) \s*
 		     (?:(<=|<) \s* ([+-.\dA-Z_][^\s]*))?
 		   /x) {
-	return ($3, $1, $2 ? $premap{$2} : $2, $5, $4 ? $postmap{$4} : $4);
+	return ($3, $1, $2, $5, $4);
     }
 }
 
diff --git a/tools/pdbgen/pdbgen.pl b/tools/pdbgen/pdbgen.pl
index 57444a0bab..57cd1e7df1 100755
--- a/tools/pdbgen/pdbgen.pl
+++ b/tools/pdbgen/pdbgen.pl
@@ -164,10 +164,10 @@ sub arrayexpand {
 
 	    # We can't have negative lengths, but let them set a min number
 	    unless (exists $arg->{type}) {
-		$arg->{type} = '0 < int32';
+		$arg->{type} = '0 <= int32';
 	    }
 	    elsif ($arg->{type} !~ /^\s*\d+\s*</) {
-		$arg->{type} = '0 < ' . $arg->{type};
+		$arg->{type} = '0 <= ' . $arg->{type};
 	    }
 
 	    $arg->{void_ret} = 1 if exists $_->{void_ret};