diff --git a/templates/webapps/galaxy/library/common/common.mako b/templates/webapps/galaxy/library/common/common.mako
index d507f5fa297..28b9664de1a 100644
--- a/templates/webapps/galaxy/library/common/common.mako
+++ b/templates/webapps/galaxy/library/common/common.mako
@@ -282,12 +282,12 @@
                                     name = 'files_0|to_posix_lines'
                                 else:
                                     name = 'to_posix_lines'
-                                uni2posix = '<input type="checkbox" name="%s" value="true"%s/>No' % ( name, checked )
+                                uni2posix = '<input type="checkbox" name="%s" value="true"%s/>Yes' % ( name, checked )
                             %>
                             ${uni2posix}
                         </div>
                         <div class="toolParamHelp" style="clear: both;">
-                            Use this option if you don't need your datasets to be converted from uni to posix line endings.
+                            Use this option if you need your datasets to be converted from uni to posix line endings.
                         </div>
                     </div>
                     <div class="form-row">
diff --git a/tools/data_source/upload.py b/tools/data_source/upload.py
index a95cba872f7..838aa069a8f 100644
--- a/tools/data_source/upload.py
+++ b/tools/data_source/upload.py
@@ -310,9 +310,9 @@ def add_file( dataset, registry, json_file, output_path ):
                     if dataset.to_posix_lines:
                         tmpdir = output_adjacent_tmpdir( output_path )
                         tmp_prefix = 'data_id_%s_convert_' % dataset.dataset_id
-                        if dataset.space_to_tab and not dataset.to_posix_lines:
+                        if dataset.space_to_tab:
                             line_count, converted_path = sniff.convert_newlines_sep2tabs( dataset.path, in_place=in_place, tmp_dir=tmpdir, tmp_prefix=tmp_prefix )
-                        elif(not dataset.to_posix_lines):
+                        else:
                             line_count, converted_path = sniff.convert_newlines( dataset.path, in_place=in_place, tmp_dir=tmpdir, tmp_prefix=tmp_prefix )
                 if dataset.file_type == 'auto':
                     ext = sniff.guess_ext( dataset.path, registry.sniff_order )