diff --git a/datasette/utils/__init__.py b/datasette/utils/__init__.py
index 5ed8dd12..1173d798 100644
--- a/datasette/utils/__init__.py
+++ b/datasette/utils/__init__.py
@@ -261,6 +261,27 @@ def escape_sqlite(s):
         return "[{}]".format(s)
 
 
+_decode_path_component_re = re.compile(r"U\+([\da-h]{4})", re.IGNORECASE)
+_encode_path_component_re = re.compile(
+    "[{}]".format(
+        "".join(
+            re.escape(c)
+            for c in (";", "/", "?", ":", "@", "&", "=", "+", "$", ",", "~")
+        )
+    )
+)
+
+
+def decode_path_component(table_name):
+    return _decode_path_component_re.sub(lambda m: chr(int(m.group(1), 16)), table_name)
+
+
+def encode_path_component(table_name):
+    return _encode_path_component_re.sub(
+        lambda m: "U+{0:0{1}x}".format(ord(m.group(0)), 4).upper(), table_name
+    )
+
+
 def make_dockerfile(
     files,
     metadata_file,