diff --git a/app/models/sqs_message.rb b/app/models/sqs_message.rb
index 55011406..0baf6c70 100644
--- a/app/models/sqs_message.rb
+++ b/app/models/sqs_message.rb
@@ -6,7 +6,7 @@ class SqsMessage
   def initialize(thesis)
     @thesis = thesis
     @package_id = "etd_#{@thesis.id}"
-    @metadata_uri = thesis.dspace_metadata.blob.url(expires_in: 604800)
+    @metadata_uri = thesis.dspace_metadata.blob.url(expires_in: 604_800)
   end
 
   def message_attributes
@@ -35,8 +35,8 @@ def map_files
            .sort_by { |item| ordered_filter.index(item[:purpose]) }
            .map do |f|
       {
-        'BitstreamName' => f.blob.filename.to_s,
-        'FileLocation' => f.blob.url(expires_in: 604800),
+        'BitstreamName' => sanitize_filename_for_dspace(f.blob.filename.to_s),
+        'FileLocation' => f.blob.url(expires_in: 604_800),
         'BitstreamDescription' => bitstream_description(f)
       }
     end
@@ -47,7 +47,7 @@ def map_files
   def collection_handle
     if @thesis.degrees.any? { |d| d.degree_type.name == 'Doctoral' }
       ENV.fetch('DSPACE_DOCTORAL_HANDLE')
-    elsif @thesis.degrees.any? { |d| d.degree_type.name == 'Master' || d.degree_type.name == 'Engineer' }
+    elsif @thesis.degrees.any? { |d| %w[Master Engineer].include?(d.degree_type.name) }
       ENV.fetch('DSPACE_GRADUATE_HANDLE')
     else
       ENV.fetch('DSPACE_UNDERGRADUATE_HANDLE')
@@ -60,4 +60,27 @@ def bitstream_description(file)
     translated_purpose = file_purposes[file.purpose]
     "#{translated_purpose} #{file.description}".strip
   end
+
+  private
+
+  # DSpace chokes on certain unicode characters. If a thesis has files that contain one of these
+  # characters, DSpace will allow publication, but it won't allow end users to download the files.
+  #
+  # This method normalizes the current known list of problematic characters:
+  # - decomposed combining diacritics
+  # - zero-width spaces (and presumably directional control characters, which are also invisible)
+  # - en-dashes (and presumably other dash variants)
+  #
+  # As we learn of other problematic characters, we should add them to this method.
+  def sanitize_filename_for_dspace(filename)
+    # Normalize to NFC (precomposed form) to fix decomposed combining marks (e.g., í as i + acute
+    # accent)
+    normalized = filename.unicode_normalize(:nfc)
+
+    # Strip zero-width and directional control characters
+    normalized = normalized.gsub(/[\u200B\u200C\u200D\u200E\u200F\u202A-\u202E]/, '')
+
+    # Replace em-dashes, en-dashes, and other dash variants with standard hyphen
+    normalized.gsub(/[\u2010-\u2015]/, '-')
+  end
 end
diff --git a/test/models/sqs_message_test.rb b/test/models/sqs_message_test.rb
index 6f6f8b03..81344094 100644
--- a/test/models/sqs_message_test.rb
+++ b/test/models/sqs_message_test.rb
@@ -50,10 +50,12 @@ def dss_friendly_thesis(thesis)
     @thesis.save
     @thesis.reload
     assert_equal 5, @thesis.files.length
-    assert_equal ['thesis_pdf', 'proquest_form', 'signature_page', 'thesis_source', 'thesis_supplementary_file'], @thesis.files.map{|f| f.purpose}
+    assert_equal(%w[thesis_pdf proquest_form signature_page thesis_source thesis_supplementary_file], @thesis.files.map do |f|
+      f.purpose
+    end)
     files = SqsMessage.new(@thesis).map_files
     assert_equal 2, files.length
-    assert_equal ['Thesis PDF My thesis', 'Supplementary file'], files.map{|f| f['BitstreamDescription']}
+    assert_equal(['Thesis PDF My thesis', 'Supplementary file'], files.map { |f| f['BitstreamDescription'] })
   end
 
   test 'thesis_pdf are attached before supplementary files' do
@@ -67,10 +69,14 @@ def dss_friendly_thesis(thesis)
     @thesis.files.last.purpose = 'thesis_supplementary_file'
     @thesis.save
     @thesis.reload
-    assert_equal ['thesis_supplementary_file', 'thesis_pdf', 'thesis_supplementary_file'], @thesis.files.map{|f| f.purpose}
+    assert_equal(%w[thesis_supplementary_file thesis_pdf thesis_supplementary_file], @thesis.files.map do |f|
+      f.purpose
+    end)
     files = SqsMessage.new(@thesis).map_files
-    assert_equal ['Thesis PDF', 'Supplementary file', 'Supplementary file'], files.map{|f| f['BitstreamDescription']}
-    assert_equal ['thesis_pdf.pdf', 'supplemental_file.pdf', 'flexible_pdf.pdf'], files.map{ |f| f['BitstreamName'] }
+    assert_equal(['Thesis PDF', 'Supplementary file', 'Supplementary file'], files.map do |f|
+      f['BitstreamDescription']
+    end)
+    assert_equal(['thesis_pdf.pdf', 'supplemental_file.pdf', 'flexible_pdf.pdf'], files.map { |f| f['BitstreamName'] })
     # Swapping file purposes will result in the same set of files being sorted into a different order. This is meant to
     # demonstrate confidence that alphabetical order is not part of the logic being used - the thesis pdf comes first,
     # followed by supplemental files in the order they were attached.
@@ -80,8 +86,10 @@ def dss_friendly_thesis(thesis)
     @thesis.files.last.purpose = 'thesis_pdf' # last-attached "flexible_pdf" should now be sorted first
     @thesis.files.second.purpose = 'thesis_supplementary_file' # second-attached "thesis_pdf" should now be sorted last
     files = SqsMessage.new(@thesis).map_files
-    assert_equal ['Thesis PDF', 'Supplementary file', 'Supplementary file'], files.map{|f| f['BitstreamDescription']}
-    assert_equal ['flexible_pdf.pdf', 'supplemental_file.pdf', 'thesis_pdf.pdf'], files.map{ |f| f['BitstreamName'] }
+    assert_equal(['Thesis PDF', 'Supplementary file', 'Supplementary file'], files.map do |f|
+      f['BitstreamDescription']
+    end)
+    assert_equal(['flexible_pdf.pdf', 'supplemental_file.pdf', 'thesis_pdf.pdf'], files.map { |f| f['BitstreamName'] })
   end
 
   test 'returns correct bitstream description' do
@@ -153,4 +161,63 @@ def dss_friendly_thesis(thesis)
     # Not checking the full URI here because ActiveStorage::SetCurrent doesn't generate URIs consistently.
     assert body_json['MetadataLocation'].ends_with?('some_file.json')
   end
+
+  test 'sanitize_filename_for_dspace normalizes decomposed unicode to precomposed' do
+    # Decomposed form: í as i (U+0069) + combining acute accent (U+0301)
+    decomposed = 'saldías_belen_thesis.pdf' # Will be NFD if created on macOS
+    sqs = SqsMessage.new(@thesis)
+    sanitized = sqs.send(:sanitize_filename_for_dspace, decomposed)
+
+    # Should normalize to precomposed form
+    assert_equal 'saldías_belen_thesis.pdf'.unicode_normalize(:nfc), sanitized
+  end
+
+  test 'sanitize_filename_for_dspace removes zero-width spaces' do
+    # Contains U+200B (zero-width space)
+    filename_with_zwsp = "Liang-thesis\u200b.pdf"
+    sqs = SqsMessage.new(@thesis)
+    sanitized = sqs.send(:sanitize_filename_for_dspace, filename_with_zwsp)
+    assert_equal 'Liang-thesis.pdf', sanitized
+  end
+
+  test 'sanitize_filename_for_dspace replaces en-dashes with hyphens' do
+    # U+2013 is en-dash
+    filename_with_endash = "Siddiqui\u2013sameed-thesis.pdf"
+    sqs = SqsMessage.new(@thesis)
+    sanitized = sqs.send(:sanitize_filename_for_dspace, filename_with_endash)
+    assert_equal 'Siddiqui-sameed-thesis.pdf', sanitized
+  end
+
+  test 'sanitize_filename_for_dspace preserves safe precomposed accented characters' do
+    # These are precomposed forms that DSpace accepts
+    safe_filenames = [
+      'garcía_thesis.pdf',      # U+00ED precomposed í
+      'strømstad_thesis.pdf',   # U+00F8 precomposed ø
+      'MillánBarea_thesis.pdf'  # U+00E1 precomposed á
+    ]
+    sqs = SqsMessage.new(@thesis)
+    safe_filenames.each do |filename|
+      sanitized = sqs.send(:sanitize_filename_for_dspace, filename)
+      assert_equal filename, sanitized, "Safe character filename was modified: #{filename}"
+    end
+  end
+
+  test 'sanitize_filename_for_dspace applied to map_files output' do
+    # Test end-to-end: verify sanitized filenames appear in map_files output
+    f = Rails.root.join('test', 'fixtures', 'files', 'a_pdf.pdf')
+    @thesis.files.detach
+
+    # Attach file with decomposed unicode (i + combining acute accent, not precomposed í)
+    decomposed_filename = "sald\u0069\u0301as_thesis.pdf"  # i (U+0069) + combining acute (U+0301)
+    @thesis.files.attach(io: File.open(f), filename: decomposed_filename)
+    @thesis.files.last.purpose = 'thesis_pdf'
+    @thesis.files.last.description = 'My thesis'
+    @thesis.save
+    @thesis.reload
+
+    files = SqsMessage.new(@thesis).map_files
+
+    # Filename should be normalized (decomposed í converted to precomposed)
+    assert_equal decomposed_filename.unicode_normalize(:nfc), files.first['BitstreamName']
+  end
 end