diff --git a/sphinx/domains/c/__init__.py b/sphinx/domains/c/__init__.py
index d02d35d97..e82912c16 100644
--- a/sphinx/domains/c/__init__.py
+++ b/sphinx/domains/c/__init__.py
@@ -259,8 +259,14 @@ class CObject(ObjectDescription[ASTDeclaration]):
             self.env.temp_data['c:last_symbol'] = e.symbol
             msg = __("Duplicate C declaration, also defined at %s:%s.\n"
                      "Declaration is '.. c:%s:: %s'.")
-            msg = msg % (e.symbol.docname, e.symbol.line, self.display_object_type, sig)
-            logger.warning(msg, location=signode)
+            logger.warning(
+                msg,
+                e.symbol.docname,
+                e.symbol.line,
+                self.display_object_type,
+                sig,
+                location=signode,
+            )
 
         if ast.objectType == 'enumerator':
             self._add_enumerator_to_parent(ast)
diff --git a/sphinx/domains/c/_symbol.py b/sphinx/domains/c/_symbol.py
index 01b159ac8..f7337a047 100644
--- a/sphinx/domains/c/_symbol.py
+++ b/sphinx/domains/c/_symbol.py
@@ -508,9 +508,14 @@ class Symbol:
                     name = str(ourChild.declaration)
                     msg = __("Duplicate C declaration, also defined at %s:%s.\n"
                              "Declaration is '.. c:%s:: %s'.")
-                    msg = msg % (ourChild.docname, ourChild.line,
-                                 ourChild.declaration.directiveType, name)
-                    logger.warning(msg, location=(otherChild.docname, otherChild.line))
+                    logger.warning(
+                        msg,
+                        ourChild.docname,
+                        ourChild.line,
+                        ourChild.declaration.directiveType,
+                        name,
+                        location=(otherChild.docname, otherChild.line),
+                    )
                 else:
                     # Both have declarations, and in the same docname.
                     # This can apparently happen, it should be safe to
diff --git a/sphinx/domains/cpp/__init__.py b/sphinx/domains/cpp/__init__.py
index 6a9756f5c..451836111 100644
--- a/sphinx/domains/cpp/__init__.py
+++ b/sphinx/domains/cpp/__init__.py
@@ -359,9 +359,14 @@ class CPPObject(ObjectDescription[ASTDeclaration]):
             self.env.temp_data['cpp:last_symbol'] = e.symbol
             msg = __("Duplicate C++ declaration, also defined at %s:%s.\n"
                      "Declaration is '.. cpp:%s:: %s'.")
-            msg = msg % (e.symbol.docname, e.symbol.line,
-                         self.display_object_type, sig)
-            logger.warning(msg, location=signode)
+            logger.warning(
+                msg,
+                e.symbol.docname,
+                e.symbol.line,
+                self.display_object_type,
+                sig,
+                location=signode,
+            )
 
         if ast.objectType == 'enumerator':
             self._add_enumerator_to_parent(ast)
diff --git a/sphinx/domains/cpp/_symbol.py b/sphinx/domains/cpp/_symbol.py
index 0a2d5ade7..1cb716955 100644
--- a/sphinx/domains/cpp/_symbol.py
+++ b/sphinx/domains/cpp/_symbol.py
@@ -792,9 +792,14 @@ class Symbol:
                     name = str(ourChild.declaration)
                     msg = __("Duplicate C++ declaration, also defined at %s:%s.\n"
                              "Declaration is '.. cpp:%s:: %s'.")
-                    msg = msg % (ourChild.docname, ourChild.line,
-                                 ourChild.declaration.directiveType, name)
-                    logger.warning(msg, location=(otherChild.docname, otherChild.line))
+                    logger.warning(
+                        msg,
+                        ourChild.docname,
+                        ourChild.line,
+                        ourChild.declaration.directiveType,
+                        name,
+                        location=(otherChild.docname, otherChild.line),
+                    )
                 else:
                     if (otherChild.declaration.objectType ==
                             ourChild.declaration.objectType and