@@ -288,10 +288,12 @@ re
 --
 
 * Character class escapes (``\d``, ``\D``, ``\s``, ``\S``, ``\w`` and ``\W``)
-  outside a character set are now compiled to a single ``CATEGORY`` opcode
-  instead of being wrapped in an ``IN`` block.  This speeds up matching of
-  patterns such as ``\d+`` and reduces the size of the compiled byte code.
-  (Contributed by Serhiy Storchaka in :gh:`152033`.)
+  outside a character set, and character sets containing a single such escape
+  (such as ``[\d]`` or ``[^\s]``), are now compiled to a single ``CATEGORY``
+  opcode instead of being wrapped in an ``IN`` block.  This speeds up matching
+  of patterns such as ``\d+`` and reduces the size of the compiled byte code.
+  (Contributed by Serhiy Storchaka in :gh:`152033` and Pieter Eendebak in
+  :gh:`152056`.)
 
 module_name
 -----------

diff --git a/Lib/re/_parser.py b/Lib/re/_parser.py
@@ -625,6 +625,12 @@ def _parse(source, state, verbose, nested, first=False):
                     subpatternappend((NOT_LITERAL, set[0][1]))
                 else:
                     subpatternappend(set[0])
+            elif _len(set) == 1 and set[0][0] is CATEGORY:
+                # optimization: a lone category like [\d] or [^\d]
+                if negate:
+                    subpatternappend((CATEGORY, CH_NEGATE[set[0][1]]))
+                else:
+                    subpatternappend(set[0])
             else:
                 if negate:
                     set.insert(0, (NEGATE, None))

diff --git a/Misc/NEWS.d/next/Library/2026-06-24-10-30-00.gh-issue-152056.Qk7mZ2.rst b/Misc/NEWS.d/next/Library/2026-06-24-10-30-00.gh-issue-152056.Qk7mZ2.rst
@@ -0,0 +1,5 @@
+Optimize matching of a character set that contains a single character
+category, such as ``[\d]`` or ``[^\s]``: it is now compiled to a single
+``CATEGORY`` opcode, the same as the corresponding ``\d`` or ``\S`` escape,
+instead of being wrapped in an ``IN`` block.  This speeds up matching and
+reduces the size of the compiled byte code.  Patch by Pieter Eendebak.