diff --git a/lib/patcher/src/_internal.ts b/lib/patcher/src/_internal.ts
index 5692448..f9fcd76 100644
--- a/lib/patcher/src/_internal.ts
+++ b/lib/patcher/src/_internal.ts
@@ -46,7 +46,7 @@ export interface InsteadHookNode<T extends UnknownFunction = UnknownFunction>
 
 /** @throws {TypeError} When `hookNode` is defined, its hook and that of all other hook nodes in its list must also be defined. */
 function applyHooks<T>(hookNode: HookNode<(arg: T) => T> | undefined, arg: T) {
-    while (hookNode !== undefined) {
+    while (hookNode) {
         // Save a reference to the next hook node in case the current hook calls unpatch.
         const { next, hook } = hookNode
         // Indirectly call the hook so as to not give it access to its hook node.
diff --git a/lib/patcher/src/hooks/after.ts b/lib/patcher/src/hooks/after.ts
index b935535..ce9b7e9 100644
--- a/lib/patcher/src/hooks/after.ts
+++ b/lib/patcher/src/hooks/after.ts
@@ -49,7 +49,7 @@ export function after<Key extends PropertyKey, Value extends UnknownFunction>(
 
     let state = patchedFunctionProxyStates.get(target)
     let hookNode: HookNode<typeof hook>
-    if (state !== undefined && state.parent === parent && state.key === key) {
+    if (state?.parent === parent && state.key === key) {
         const head = state.after
         hookNode = {
             hook,
@@ -57,7 +57,7 @@ export function after<Key extends PropertyKey, Value extends UnknownFunction>(
             prev: undefined,
             unpatched: false,
         }
-        if (head !== undefined) head.prev = hookNode
+        if (head) head.prev = hookNode
         state.after = hookNode
     } else {
         hookNode = {
diff --git a/lib/patcher/src/hooks/before.ts b/lib/patcher/src/hooks/before.ts
index d144ea2..944de9e 100644
--- a/lib/patcher/src/hooks/before.ts
+++ b/lib/patcher/src/hooks/before.ts
@@ -49,7 +49,7 @@ export function before<Key extends PropertyKey, Value extends UnknownFunction>(
 
     let state = patchedFunctionProxyStates.get(target)
     let hookNode: HookNode<typeof hook>
-    if (state !== undefined && state.parent === parent && state.key === key) {
+    if (state?.parent === parent && state.key === key) {
         const head = state.before
         hookNode = {
             hook,
@@ -57,7 +57,7 @@ export function before<Key extends PropertyKey, Value extends UnknownFunction>(
             prev: undefined,
             unpatched: false,
         }
-        if (head !== undefined) head.prev = hookNode
+        if (head) head.prev = hookNode
         state.before = hookNode
     } else {
         hookNode = {
diff --git a/lib/patcher/src/hooks/instead.ts b/lib/patcher/src/hooks/instead.ts
index 417be7f..1e2ec11 100644
--- a/lib/patcher/src/hooks/instead.ts
+++ b/lib/patcher/src/hooks/instead.ts
@@ -96,10 +96,10 @@ export function instead<Key extends PropertyKey, Value extends UnknownFunction>(
     hookNode.hook = hook
     hookNode.prev = undefined
 
-    if (state !== undefined && state.parent === parent && state.key === key) {
+    if (state?.parent === parent && state.key === key) {
         const head = state.instead
         hookNode.next = head
-        if (head !== undefined) head.prev = hookNode
+        if (head) head.prev = hookNode
         state.instead = hookNode
     } else {
         hookNode.next = undefined