diff --git a/cpp/common/src/codingstandards/cpp/exclusions/cpp/Declarations5.qll b/cpp/common/src/codingstandards/cpp/exclusions/cpp/Declarations5.qll
new file mode 100644
index 000000000..ff4806a5b
--- /dev/null
+++ b/cpp/common/src/codingstandards/cpp/exclusions/cpp/Declarations5.qll
@@ -0,0 +1,44 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype Declarations5Query =
+  TMemberFunctionsRefqualifiedQuery() or
+  TTypeAliasesDeclarationQuery()
+
+predicate isDeclarations5QueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `memberFunctionsRefqualified` query
+    Declarations5Package::memberFunctionsRefqualifiedQuery() and
+  queryId =
+    // `@id` for the `memberFunctionsRefqualified` query
+    "cpp/misra/member-functions-refqualified" and
+  ruleId = "RULE-6-8-4" and
+  category = "advisory"
+  or
+  query =
+    // `Query` instance for the `typeAliasesDeclaration` query
+    Declarations5Package::typeAliasesDeclarationQuery() and
+  queryId =
+    // `@id` for the `typeAliasesDeclaration` query
+    "cpp/misra/type-aliases-declaration" and
+  ruleId = "RULE-6-9-1" and
+  category = "required"
+}
+
+module Declarations5Package {
+  Query memberFunctionsRefqualifiedQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `memberFunctionsRefqualified` query
+      TQueryCPP(TDeclarations5PackageQuery(TMemberFunctionsRefqualifiedQuery()))
+  }
+
+  Query typeAliasesDeclarationQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `typeAliasesDeclaration` query
+      TQueryCPP(TDeclarations5PackageQuery(TTypeAliasesDeclarationQuery()))
+  }
+}
diff --git a/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll b/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll
index 652d12307..f7a0fac93 100644
--- a/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll
+++ b/cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll
@@ -33,6 +33,7 @@ import DeadCode8
 import DeadCode9
 import Declarations
 import Declarations1
+import Declarations5
 import ExceptionSafety
 import Exceptions1
 import Exceptions2
@@ -129,6 +130,7 @@ newtype TCPPQuery =
   TDeadCode9PackageQuery(DeadCode9Query q) or
   TDeclarationsPackageQuery(DeclarationsQuery q) or
   TDeclarations1PackageQuery(Declarations1Query q) or
+  TDeclarations5PackageQuery(Declarations5Query q) or
   TExceptionSafetyPackageQuery(ExceptionSafetyQuery q) or
   TExceptions1PackageQuery(Exceptions1Query q) or
   TExceptions2PackageQuery(Exceptions2Query q) or
@@ -225,6 +227,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isDeadCode9QueryMetadata(query, queryId, ruleId, category) or
   isDeclarationsQueryMetadata(query, queryId, ruleId, category) or
   isDeclarations1QueryMetadata(query, queryId, ruleId, category) or
+  isDeclarations5QueryMetadata(query, queryId, ruleId, category) or
   isExceptionSafetyQueryMetadata(query, queryId, ruleId, category) or
   isExceptions1QueryMetadata(query, queryId, ruleId, category) or
   isExceptions2QueryMetadata(query, queryId, ruleId, category) or
diff --git a/cpp/misra/src/rules/RULE-6-9-1/TypeAliasesDeclaration.ql b/cpp/misra/src/rules/RULE-6-9-1/TypeAliasesDeclaration.ql
new file mode 100644
index 000000000..d8898377d
--- /dev/null
+++ b/cpp/misra/src/rules/RULE-6-9-1/TypeAliasesDeclaration.ql
@@ -0,0 +1,33 @@
+/**
+ * @id cpp/misra/type-aliases-declaration
+ * @name RULE-6-9-1: The same type aliases shall be used in all declarations of the same entity
+ * @description Using different type aliases on redeclarations can make code hard to understand and
+ *              maintain.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-6-9-1
+ *       maintainability
+ *       readability
+ *       scope/single-translation-unit
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.cpp.misra
+
+from DeclarationEntry decl1, DeclarationEntry decl2, TypedefType t
+where
+  not isExcluded(decl1, Declarations5Package::typeAliasesDeclarationQuery()) and
+  not isExcluded(decl2, Declarations5Package::typeAliasesDeclarationQuery()) and
+  not decl1 = decl2 and
+  decl1.getDeclaration() = decl2.getDeclaration() and
+  t.getATypeNameUse() = decl1 and
+  not t.getATypeNameUse() = decl2 and
+  //exception cases - we dont want to disallow struct typedef name use
+  not t.getBaseType() instanceof Struct and
+  not t.getBaseType() instanceof Enum
+select decl1,
+  "Declaration entry has a different type alias than $@ where the type alias used is '$@'.", decl2,
+  decl2.getName(), t, t.getName()
diff --git a/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.expected b/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.expected
new file mode 100644
index 000000000..db0ef7b72
--- /dev/null
+++ b/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.expected
@@ -0,0 +1,2 @@
+| test.cpp:4:5:4:5 | definition of i | Declaration entry has a different type alias than $@ where the type alias used is '$@'. | test.cpp:5:12:5:12 | declaration of i | i | test.cpp:1:13:1:15 | INT | INT |
+| test.cpp:11:20:11:20 | declaration of i | Declaration entry has a different type alias than $@ where the type alias used is '$@'. | test.cpp:10:12:10:12 | declaration of i | i | test.cpp:2:7:2:11 | Index | Index |
diff --git a/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.qlref b/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.qlref
new file mode 100644
index 000000000..a3cf4823c
--- /dev/null
+++ b/cpp/misra/test/rules/RULE-6-9-1/TypeAliasesDeclaration.qlref
@@ -0,0 +1 @@
+rules/RULE-6-9-1/TypeAliasesDeclaration.ql
\ No newline at end of file
diff --git a/cpp/misra/test/rules/RULE-6-9-1/test.cpp b/cpp/misra/test/rules/RULE-6-9-1/test.cpp
new file mode 100644
index 000000000..dfc18becf
--- /dev/null
+++ b/cpp/misra/test/rules/RULE-6-9-1/test.cpp
@@ -0,0 +1,15 @@
+typedef int INT;
+using Index = int;
+
+INT i;
+extern int i; // NON_COMPLIANT
+
+INT j;
+extern INT j; // COMPLIANT
+
+void g(int i);
+void g(Index const i); // NON_COMPLIANT
+
+void h(Index i);
+void h(Index const i); // COMPLIANT
+void h(int *i);        // COMPLIANT
\ No newline at end of file
diff --git a/rule_packages/cpp/Declarations5.json b/rule_packages/cpp/Declarations5.json
new file mode 100644
index 000000000..4f4c08e7d
--- /dev/null
+++ b/rule_packages/cpp/Declarations5.json
@@ -0,0 +1,47 @@
+{
+  "MISRA-C++-2023": {
+    "RULE-6-8-4": {
+      "properties": {
+        "enforcement": "decidable",
+        "obligation": "advisory"
+      },
+      "queries": [
+        {
+          "description": "Member functions that return references to temporary objects (or subobjects) can lead to dangling pointers.",
+          "kind": "problem",
+          "name": "Member functions returning references to their object should be refqualified appropriately",
+          "precision": "very-high",
+          "severity": "error",
+          "short_name": "MemberFunctionsRefqualified",
+          "tags": [
+            "correctness",
+            "scope/single-translation-unit"
+          ]
+        }
+      ],
+      "title": "Member functions returning references to their object should be refqualified appropriately"
+    },
+    "RULE-6-9-1": {
+      "properties": {
+        "enforcement": "decidable",
+        "obligation": "required"
+      },
+      "queries": [
+        {
+          "description": "Using different type aliases on redeclarations can make code hard to understand and maintain.",
+          "kind": "problem",
+          "name": "The same type aliases shall be used in all declarations of the same entity",
+          "precision": "very-high",
+          "severity": "warning",
+          "short_name": "TypeAliasesDeclaration",
+          "tags": [
+            "maintainability",
+            "readability",
+            "scope/single-translation-unit"
+          ]
+        }
+      ],
+      "title": "The same type aliases shall be used in all declarations of the same entity"
+    }
+  }
+}
\ No newline at end of file
diff --git a/rules.csv b/rules.csv
index 008020f37..7863e5791 100644
--- a/rules.csv
+++ b/rules.csv
@@ -867,8 +867,8 @@ cpp,MISRA-C++-2023,RULE-6-7-2,Yes,Required,Decidable,Single Translation Unit,Glo
 cpp,MISRA-C++-2023,RULE-6-8-1,Yes,Required,Undecidable,System,An object shall not be accessed outside of its lifetime,A3-8-1,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-8-2,Yes,Mandatory,Decidable,Single Translation Unit,A function must not return a reference or a pointer to a local variable with automatic storage duration,M7-5-1,ImportMisra23,Import,
 cpp,MISRA-C++-2023,RULE-6-8-3,Yes,Required,Decidable,Single Translation Unit,An assignment operator shall not assign the address of an object with automatic storage duration to an object with a greater lifetime,,Lifetime,Medium,
-cpp,MISRA-C++-2023,RULE-6-8-4,Yes,Advisory,Decidable,Single Translation Unit,Member functions returning references to their object should be refqualified appropriately,,Declarations2,Medium,
-cpp,MISRA-C++-2023,RULE-6-9-1,Yes,Required,Decidable,Single Translation Unit,The same type aliases shall be used in all declarations of the same entity,,Declarations2,Medium,
+cpp,MISRA-C++-2023,RULE-6-8-4,Yes,Advisory,Decidable,Single Translation Unit,Member functions returning references to their object should be refqualified appropriately,,Declarations5,Medium,
+cpp,MISRA-C++-2023,RULE-6-9-1,Yes,Required,Decidable,Single Translation Unit,The same type aliases shall be used in all declarations of the same entity,,Declarations5,Medium,
 cpp,MISRA-C++-2023,RULE-6-9-2,Yes,Advisory,Decidable,Single Translation Unit,The names of the standard signed integer types and standard unsigned integer types should not be used,A3-9-1,BannedAPIs,Easy,
 cpp,MISRA-C++-2023,RULE-7-0-1,Yes,Required,Decidable,Single Translation Unit,There shall be no conversion from type bool,,Conversions,Easy,
 cpp,MISRA-C++-2023,RULE-7-0-2,Yes,Required,Decidable,Single Translation Unit,There shall be no conversion to type bool,,Conversions,Easy,