diff --git a/linter.py b/linter.py
index a7f9145..07cadce 100644
--- a/linter.py
+++ b/linter.py
@@ -108,6 +108,12 @@ def parse_output(self, proc, virtual_view):
 
         return filtered_errors
 
+    def convert_column(self, line, col, m, vv):
+        # Pyflakes' AST positions are bytes; pycodestyle positions are characters.
+        if m.code.startswith('F'):
+            return vv.col_from_utf8(line, col)
+        return super().convert_column(line, col, m, vv)
+
     def reposition_match(self, line, col, m, virtual_view):
         """Reposition white-space errors."""
         code = m.code
diff --git a/tests/test_columns.py b/tests/test_columns.py
new file mode 100644
index 0000000..1b3f0db
--- /dev/null
+++ b/tests/test_columns.py
@@ -0,0 +1,45 @@
+import importlib
+import unittest
+
+import sublime
+from SublimeLinter.lint.linter import VirtualView
+
+
+Linter = importlib.import_module('SublimeLinter-flake8.linter').Flake8
+
+
+class TestColumns(unittest.TestCase):
+    def test_pyflakes_bytes_and_pycodestyle_characters_together(self):
+        # Captured Flake8 7.4.1 output for the same source line.
+        output = ("stdin:1:15: F821 undefined name 'missing_name'\n"
+                  "stdin:1:9: E702 multiple statements on one line (semicolon)\n")
+        self.assertDiagnostics(output, 's = "é😀"; missing_name\n', [(10, 'missing_name'), (8, ';')])
+
+    def test_pycodestyle_operator_position_is_unchanged(self):
+        output = 'stdin:1:2: E225 missing whitespace around operator'
+        self.assertDiagnostics(output, 's="é😀"\n', [(1, '=')])
+
+    def test_trailing_whitespace_repositioning_is_preserved(self):
+        self.assertDiagnostics('stdin:1:9: W291 trailing whitespace', 's = "é😀"   \n', [(8, '   ')])
+
+    def test_unused_import_repositioning_is_preserved(self):
+        output = "stdin:1:1: F401 'os.path' imported but unused"
+        self.assertDiagnostics(output, 'from os import path\n', [(15, 'path')])
+
+    def test_ascii_pyflakes_position_is_unchanged(self):
+        output = "stdin:1:1: F821 undefined name 'missing_name'"
+        self.assertDiagnostics(output, 'missing_name\n', [(0, 'missing_name')])
+
+    def assertDiagnostics(self, output, source, expected):
+        linter = Linter(sublime.View(0), {})
+        matches = list(linter.find_errors(output))
+        self.assertEqual(len(matches), len(expected))
+        for match, (col, text) in zip(matches, expected):
+            before = dict(match)
+            error = linter.process_match(match, VirtualView(source))
+            self.assertIsNotNone(error)
+            self.assertEqual(match, before)
+            self.assertEqual({k: error[k] for k in ('line', 'start', 'region', 'offending_text')}, {
+                'line': 0, 'start': col, 'region': sublime.Region(col, col + len(text)),
+                'offending_text': text,
+            })