diff --git a/Lib/_ast_unparse.py b/Lib/_ast_unparse.py
index 916bb25d74dee9b..58bc06397f5134b 100644
--- a/Lib/_ast_unparse.py
+++ b/Lib/_ast_unparse.py
@@ -925,7 +925,11 @@ def visit_Attribute(self, node):
         # Special case: 3.__abs__() is a syntax error, so if node.value
         # is an integer literal then we need to either parenthesize
         # it or add an extra space to get 3 .__abs__().
-        if isinstance(node.value, Constant) and isinstance(node.value.value, int):
+        # bool is a subclass of int, but True.real and False.real are
+        # valid without a space.
+        if (isinstance(node.value, Constant)
+                and isinstance(node.value.value, int)
+                and not isinstance(node.value.value, bool)):
             self.write(" ")
         self.write(".")
         self.write(node.attr)
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index 9bc04fc8e0affb9..b1f359764fa4fed 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -335,6 +335,14 @@ def test_unary_parens(self):
     def test_integer_parens(self):
         self.check_ast_roundtrip("3 .__abs__()")
 
+    def test_attribute_on_bool(self):
+        # gh-158237: True.real should not gain a space
+        self.check_src_roundtrip("x = True.real")
+        self.check_src_roundtrip("x = False.__class__")
+
+    def test_attribute_on_int_still_spaced(self):
+        self.check_src_roundtrip("x = 3 .__abs__()")
+
     def test_huge_float(self):
         self.check_ast_roundtrip("1e1000")
         self.check_ast_roundtrip("-1e1000")
diff --git a/Misc/NEWS.d/next/Library/2026-09-26-22-07-09.gh-issue-158237.AbCdEf.rst b/Misc/NEWS.d/next/Library/2026-09-26-22-07-09.gh-issue-158237.AbCdEf.rst
new file mode 100644
index 000000000000000..1c28e527dea042e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-09-26-22-07-09.gh-issue-158237.AbCdEf.rst
@@ -0,0 +1,3 @@
+Fix :func:`ast.unparse` to not insert a space before attribute
+access on bool constants (e.g. ``True.real`` instead of
+``True .real``).