diff --git a/CHANGELOG.md b/CHANGELOG.md
index e81e6ba47..ac9824c6a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 - Add experimental unused import analysis.
 - The option `--external-encodable-protocols` is deprecated, use `--external-codable-protocols` instead.
+- CodingKey enum case are now identified as unused if the corresponding property is also unused in the Codable type.
 
 ##### Bug Fixes
 
diff --git a/Sources/PeripheryKit/SourceGraph/Mutators/CodingKeyEnumReferenceBuilder.swift b/Sources/PeripheryKit/SourceGraph/Mutators/CodingKeyEnumReferenceBuilder.swift
index f7320dd65..93ac39b75 100644
--- a/Sources/PeripheryKit/SourceGraph/Mutators/CodingKeyEnumReferenceBuilder.swift
+++ b/Sources/PeripheryKit/SourceGraph/Mutators/CodingKeyEnumReferenceBuilder.swift
@@ -26,12 +26,28 @@ final class CodingKeyEnumReferenceBuilder: SourceGraphMutator {
                 return [.protocol, .typealias].contains($0.kind) && codableTypes.contains(name)
             }
 
-            if isCodingKey && isParentCodable {
-                for usr in enumDeclaration.usrs {
-                    let newReference = Reference(kind: .enum, usr: usr, location: enumDeclaration.location)
-                    newReference.name = enumDeclaration.name
-                    newReference.parent = parent
-                    graph.add(newReference, from: parent)
+            guard isCodingKey, isParentCodable else { continue }
+
+            // Build a reference from the Codable type to the CodingKey enum.
+            for usr in enumDeclaration.usrs {
+                let newReference = Reference(kind: .enum, usr: usr, location: enumDeclaration.location)
+                newReference.name = enumDeclaration.name
+                newReference.parent = parent
+                graph.add(newReference, from: parent)
+            }
+
+            // For each property in the Codable type, build a reference to its corresponding
+            // CodingKey enum element.
+            for decl in parent.declarations {
+                guard decl.kind == .varInstance,
+                      let enumCase = enumDeclaration.declarations.first(where: { $0.kind == .enumelement && $0.name == decl.name })
+                else { continue }
+
+                for usr in enumCase.usrs {
+                    let newReference = Reference(kind: .enumelement, usr: usr, location: decl.location)
+                    newReference.name = enumCase.name
+                    newReference.parent = decl
+                    graph.add(newReference, from: decl)
                 }
             }
         }
diff --git a/Sources/PeripheryKit/SourceGraph/Mutators/EncodablePropertyRetainer.swift b/Sources/PeripheryKit/SourceGraph/Mutators/EncodablePropertyRetainer.swift
deleted file mode 100644
index 0408b6835..000000000
--- a/Sources/PeripheryKit/SourceGraph/Mutators/EncodablePropertyRetainer.swift
+++ /dev/null
@@ -1,51 +0,0 @@
-import Foundation
-import Shared
-
-/// Retains properties of discrete conforming declarations that directly, or indirectly conform to `Encodable`.
-///
-/// The Swift compiler synthesizes code for `Encodable` that is not exposed in the index store. We therefore must
-/// assume that all properties are in use, as they may be referenced by synthesized code.
-final class EncodablePropertyRetainer: SourceGraphMutator {
-    private let graph: SourceGraph
-    private let externalCodableProtocols: [String]
-
-    required init(graph: SourceGraph, configuration: Configuration) {
-        self.graph = graph
-        self.externalCodableProtocols = configuration.externalEncodableProtocols + configuration.externalCodableProtocols
-    }
-
-    func mutate() {
-        graph
-            .declarations(ofKinds: Declaration.Kind.discreteConformableKinds)
-            .lazy
-            .filter { self.hasEncodableConformance($0) }
-            .forEach {
-                $0.declarations
-                    .lazy
-                    .filter { $0.kind == .varInstance }
-                    .forEach { graph.markRetained($0) }
-            }
-    }
-
-    // MARK: - Private
-
-    private func hasEncodableConformance(_ decl: Declaration) -> Bool {
-        graph
-            .inheritedTypeReferences(of: decl)
-            .contains { isEncodableReference($0) }
-    }
-
-    private func isEncodableReference(_ ref: Reference) -> Bool {
-        if ref.kind == .protocol && ref.name == "Encodable" || ref.kind == .typealias && ref.name == "Codable" {
-            return true
-        }
-
-        if let name = ref.name {
-            if graph.isExternal(ref), externalCodableProtocols.contains(name) {
-                return true
-            }
-        }
-
-        return false
-    }
-}
diff --git a/Sources/PeripheryKit/SourceGraph/SourceGraphMutatorRunner.swift b/Sources/PeripheryKit/SourceGraph/SourceGraphMutatorRunner.swift
index 91752a223..28e9b3014 100644
--- a/Sources/PeripheryKit/SourceGraph/SourceGraphMutatorRunner.swift
+++ b/Sources/PeripheryKit/SourceGraph/SourceGraphMutatorRunner.swift
@@ -38,7 +38,6 @@ public final class SourceGraphMutatorRunner {
         PubliclyAccessibleRetainer.self,
         XCTestRetainer.self,
         SwiftUIRetainer.self,
-        EncodablePropertyRetainer.self,
         StringInterpolationAppendInterpolationRetainer.self,
         PropertyWrapperRetainer.self,
         ResultBuilderRetainer.self,
diff --git a/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift b/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
index f52c3e352..e4c5fafeb 100644
--- a/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
+++ b/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
@@ -62,3 +62,13 @@ public struct FixtureClass218: CustomStringConvertible {
         case someVar
     }
 }
+
+public class FixtureClass220: Encodable {
+    public var someUsedVar: String?
+    var someUnusedVar: String?
+
+    enum CodingKeys: CodingKey {
+        case someUsedVar
+        case someUnusedVar
+    }
+}
diff --git a/Tests/PeripheryTests/RetentionTest.swift b/Tests/PeripheryTests/RetentionTest.swift
index bd35faf08..389385f6d 100644
--- a/Tests/PeripheryTests/RetentionTest.swift
+++ b/Tests/PeripheryTests/RetentionTest.swift
@@ -574,6 +574,15 @@ final class RetentionTest: FixtureSourceGraphTestCase {
             assertReferenced(.struct("FixtureClass218")) {
                 self.assertReferenced(.enum("CodingKeys"))
             }
+            assertReferenced(.class("FixtureClass220")) {
+                self.assertReferenced(.varInstance("someUsedVar"))
+                self.assertNotReferenced(.varInstance("someUnusedVar"))
+
+                self.assertReferenced(.enum("CodingKeys")) {
+                    self.assertReferenced(.enumelement("someUsedVar"))
+                    self.assertNotReferenced(.enumelement("someUnusedVar"))
+                }
+            }
         }
     }
 
@@ -951,43 +960,6 @@ final class RetentionTest: FixtureSourceGraphTestCase {
         }
     }
 
-    func testRetainsEncodableProperties() {
-        let configuration = Configuration.shared
-        // CustomStringConvertible doesn't actually inherit Encodable, we're just using it because we don't have an
-        // external module in which to declare our own type.
-        configuration.externalCodableProtocols = ["CustomStringConvertible"]
-
-        analyze(retainPublic: true) {
-            self.assertReferenced(.class("FixtureClass204")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass205")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass206")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass207")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass208")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass209")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-
-            self.assertReferenced(.class("FixtureClass210")) {
-                self.assertReferenced(.varInstance("someVar"))
-            }
-        }
-    }
-
     func testCircularTypeInheritance() {
         analyze {
             // Intentionally blank.