diff --git a/pdb/groups/plug_in_compat.pdb b/pdb/groups/plug_in_compat.pdb
index f43876644e..b5c0b4f708 100644
--- a/pdb/groups/plug_in_compat.pdb
+++ b/pdb/groups/plug_in_compat.pdb
@@ -3821,9 +3821,9 @@ sub plug_in_sinus {
         { name => 'col2', type => 'color',
 	  desc => 'second color (sometimes unused)' },
         { name => 'alpha1', type => '0 <= float <= 1',
-	  desc => 'alpha for the first color (used if the drawable has an alpha chanel)' },
+	  desc => 'alpha for the first color (used if the drawable has an alpha channel)' },
         { name => 'alpha2', type => '0 <= float <= 1',
-	  desc => 'alpha for the second color (used if the drawable has an alpha chanel)' },
+	  desc => 'alpha for the second color (used if the drawable has an alpha channel)' },
         { name => 'blend', type => '0 <= int32 <= 2',
 	  desc => '0=linear, 1=bilinear, 2=sinusoidal' },
         { name => 'blend_power', type => 'float',