diff --git a/checker/check_response_property_type_changed_test.go b/checker/check_response_property_type_changed_test.go
index 4abc8338..eccaf98d 100644
--- a/checker/check_response_property_type_changed_test.go
+++ b/checker/check_response_property_type_changed_test.go
@@ -146,3 +146,47 @@ func TestResponseSchemaTypeMultiCheck(t *testing.T) {
 		OperationId: "createOneGroup",
 	}, errs[0])
 }
+
+// BC: changing an additionalResponse property schema type from integer to string is breaking
+func TestResponseAdditionalPropertyTypeChangedCheck(t *testing.T) {
+	s1, err := open("../data/additional-properties/base.yaml")
+	require.NoError(t, err)
+	s2, err := open("../data/additional-properties/revision.yaml")
+	require.NoError(t, err)
+
+	d, osm, err := diff.GetWithOperationsSourcesMap(diff.NewConfig(), s1, s2)
+	require.NoError(t, err)
+	errs := checker.CheckBackwardCompatibilityUntilLevel(singleCheckConfig(checker.ResponsePropertyTypeChangedCheck), d, osm, checker.ERR)
+	require.Len(t, errs, 1)
+	require.Equal(t, checker.ApiChange{
+		Id:          checker.ResponsePropertyTypeChangedId,
+		Args:        []any{"/additionalProperties/property1", utils.StringList{"integer"}, "", utils.StringList{"string"}, "", "200"},
+		Level:       checker.ERR,
+		Operation:   "GET",
+		Path:        "/value",
+		Source:      load.NewSource("../data/additional-properties/revision.yaml"),
+		OperationId: "get_value",
+	}, errs[0])
+}
+
+// BC: changing an embedded additionalResponse property schema type from integer to string is breaking
+func TestResponseEmbeddedAdditionalPropertyTypeChangedCheck(t *testing.T) {
+	s1, err := open("../data/additional-properties/embedded-base.yaml")
+	require.NoError(t, err)
+	s2, err := open("../data/additional-properties/embedded-revision.yaml")
+	require.NoError(t, err)
+
+	d, osm, err := diff.GetWithOperationsSourcesMap(diff.NewConfig(), s1, s2)
+	require.NoError(t, err)
+	errs := checker.CheckBackwardCompatibilityUntilLevel(singleCheckConfig(checker.ResponsePropertyTypeChangedCheck), d, osm, checker.ERR)
+	require.Len(t, errs, 1)
+	require.Equal(t, checker.ApiChange{
+		Id:          checker.ResponsePropertyTypeChangedId,
+		Args:        []any{"composite-property/additionalProperties/property1", utils.StringList{"integer"}, "", utils.StringList{"string"}, "", "200"},
+		Level:       checker.ERR,
+		Operation:   "GET",
+		Path:        "/value",
+		Source:      load.NewSource("../data/additional-properties/embedded-revision.yaml"),
+		OperationId: "get_value",
+	}, errs[0])
+}
diff --git a/checker/checks-utils.go b/checker/checks-utils.go
index 5181eddc..4b84a005 100644
--- a/checker/checks-utils.go
+++ b/checker/checks-utils.go
@@ -105,6 +105,10 @@ func processModifiedPropertiesDiff(propertyPath string, propertyName string, sch
 			processModifiedPropertiesDiff(propertyPath, i, v, schemaDiff, processor)
 		}
 	}
+
+	if schemaDiff.AdditionalPropertiesDiff != nil {
+		processModifiedPropertiesDiff(fmt.Sprintf("%s/additionalProperties", propertyPath), "", schemaDiff.AdditionalPropertiesDiff, schemaDiff, processor)
+	}
 }
 
 func CheckAddedPropertiesDiff(schemaDiff *diff.SchemaDiff, processor func(propertyPath string, propertyName string, propertyItem *openapi3.Schema, propertyParentDiff *diff.SchemaDiff)) {
diff --git a/data/additional-properties/base.yaml b/data/additional-properties/base.yaml
new file mode 100644
index 00000000..16826ae9
--- /dev/null
+++ b/data/additional-properties/base.yaml
@@ -0,0 +1,28 @@
+openapi: 3.0.1
+info:
+  title: Test API
+  version: v1
+components:
+  schemas:
+    Schema1:
+      properties:
+        property1:
+          title: Value
+          type: integer
+      type: object
+    Schema2:
+      additionalProperties:
+        "$ref": "#/components/schemas/Schema1"
+      title: Composite
+      type: object
+paths:
+  "/value":
+    get:
+      operationId: get_value
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Schema2"
+          description: Successful Response
diff --git a/data/additional-properties/embedded-base.yaml b/data/additional-properties/embedded-base.yaml
new file mode 100644
index 00000000..540d477e
--- /dev/null
+++ b/data/additional-properties/embedded-base.yaml
@@ -0,0 +1,31 @@
+openapi: 3.0.1
+info:
+  title: Test API
+  version: v1
+components:
+  schemas:
+    Schema1:
+      properties:
+        property1:
+          title: Value
+          type: integer
+      type: object
+    Schema2:
+      properties:
+        composite-property:
+          additionalProperties:
+            "$ref": "#/components/schemas/Schema1"
+          title: Composite
+          type: object
+      type: object
+paths:
+  "/value":
+    get:
+      operationId: get_value
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Schema2"
+          description: Successful Response
diff --git a/data/additional-properties/embedded-revision.yaml b/data/additional-properties/embedded-revision.yaml
new file mode 100644
index 00000000..14f7ca31
--- /dev/null
+++ b/data/additional-properties/embedded-revision.yaml
@@ -0,0 +1,31 @@
+openapi: 3.0.1
+info:
+  title: Test API
+  version: v1
+components:
+  schemas:
+    Schema1:
+      properties:
+        property1:
+          title: Value
+          type: string
+      type: object
+    Schema2:
+      properties:
+        composite-property:
+          additionalProperties:
+            "$ref": "#/components/schemas/Schema1"
+          title: Composite
+          type: object
+      type: object
+paths:
+  "/value":
+    get:
+      operationId: get_value
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Schema2"
+          description: Successful Response
diff --git a/data/additional-properties/revision.yaml b/data/additional-properties/revision.yaml
new file mode 100644
index 00000000..40b16d59
--- /dev/null
+++ b/data/additional-properties/revision.yaml
@@ -0,0 +1,28 @@
+openapi: 3.0.1
+info:
+  title: Test API
+  version: v1
+components:
+  schemas:
+    Schema1:
+      properties:
+        property1:
+          title: Value
+          type: string
+      type: object
+    Schema2:
+      additionalProperties:
+        "$ref": "#/components/schemas/Schema1"
+      title: Composite
+      type: object
+paths:
+  "/value":
+    get:
+      operationId: get_value
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Schema2"
+          description: Successful Response
diff --git a/docs/BREAKING-CHANGES-EXAMPLES.md b/docs/BREAKING-CHANGES-EXAMPLES.md
index 8862f666..b4a0cbbe 100644
--- a/docs/BREAKING-CHANGES-EXAMPLES.md
+++ b/docs/BREAKING-CHANGES-EXAMPLES.md
@@ -15,6 +15,8 @@ These examples are automatically generated from unit tests.
 [changing a response body to nullable is breaking](../checker/check_breaking_property_test.go?plain=1#L217)  
 [changing a response property to nullable is breaking](../checker/check_breaking_property_test.go?plain=1#L249)  
 [changing a response property to optional under AllOf, AnyOf or OneOf is breaking](../checker/check_breaking_property_test.go?plain=1#L660)  
+[changing an additionalResponse property schema type from integer to string is breaking](../checker/check_response_property_type_changed_test.go?plain=1#L150)  
+[changing an embedded additionalResponse property schema type from integer to string is breaking](../checker/check_response_property_type_changed_test.go?plain=1#L172)  
 [changing an embedded response property to nullable is breaking](../checker/check_breaking_property_test.go?plain=1#L265)  
 [changing an existing header param from optional to required is breaking](../checker/check_breaking_test.go?plain=1#L190)  
 [changing an existing path param to enum is breaking](../checker/check_breaking_property_test.go?plain=1#L185)