diff --git a/library/xof/api/xof.klib.api b/library/xof/api/xof.klib.api
index 3ae2fbb..30b219c 100644
--- a/library/xof/api/xof.klib.api
+++ b/library/xof/api/xof.klib.api
@@ -37,9 +37,9 @@ sealed class <#A: org.kotlincrypto.core.xof/XofAlgorithm> org.kotlincrypto.core.
         final fun <get-delegate>(): #A // org.kotlincrypto.core.xof/Xof.delegate.<get-delegate>|<get-delegate>(){}[0]
 
     abstract fun newReader(): org.kotlincrypto.core.xof/Xof.Reader<#A> // org.kotlincrypto.core.xof/Xof.newReader|newReader(){}[0]
-    final fun <#A1: kotlin/Any?> use(kotlin/Boolean =..., kotlin/Function1<org.kotlincrypto.core.xof/Xof.Reader<#A>, #A1>): #A1 // org.kotlincrypto.core.xof/Xof.use|use(kotlin.Boolean;kotlin.Function1<org.kotlincrypto.core.xof.Xof.Reader<1:0>,0:0>){0§<kotlin.Any?>}[0]
     final fun reader(kotlin/Boolean =...): org.kotlincrypto.core.xof/Xof.Reader<#A> // org.kotlincrypto.core.xof/Xof.reader|reader(kotlin.Boolean){}[0]
     final fun toString(): kotlin/String // org.kotlincrypto.core.xof/Xof.toString|toString(){}[0]
+    final inline fun <#A1: kotlin/Any?> use(kotlin/Boolean =..., kotlin/Function1<org.kotlincrypto.core.xof/Xof.Reader<#A>, #A1>): #A1 // org.kotlincrypto.core.xof/Xof.use|use(kotlin.Boolean;kotlin.Function1<org.kotlincrypto.core.xof.Xof.Reader<1:0>,0:0>){0§<kotlin.Any?>}[0]
 
     abstract inner class Reader { // org.kotlincrypto.core.xof/Xof.Reader|null[0]
         constructor <init>() // org.kotlincrypto.core.xof/Xof.Reader.<init>|<init>(){}[0]
@@ -52,11 +52,11 @@ sealed class <#A: org.kotlincrypto.core.xof/XofAlgorithm> org.kotlincrypto.core.
 
         abstract fun closeProtected() // org.kotlincrypto.core.xof/Xof.Reader.closeProtected|closeProtected(){}[0]
         abstract fun readProtected(kotlin/ByteArray, kotlin/Int, kotlin/Int): kotlin/Int // org.kotlincrypto.core.xof/Xof.Reader.readProtected|readProtected(kotlin.ByteArray;kotlin.Int;kotlin.Int){}[0]
-        final fun <#A2: kotlin/Any?> use(kotlin/Function1<org.kotlincrypto.core.xof/Xof.Reader<#A>, #A2>): #A2 // org.kotlincrypto.core.xof/Xof.Reader.use|use(kotlin.Function1<org.kotlincrypto.core.xof.Xof.Reader<2:0>,0:0>){0§<kotlin.Any?>}[0]
         final fun close() // org.kotlincrypto.core.xof/Xof.Reader.close|close(){}[0]
         final fun read(kotlin/ByteArray): kotlin/Int // org.kotlincrypto.core.xof/Xof.Reader.read|read(kotlin.ByteArray){}[0]
         final fun read(kotlin/ByteArray, kotlin/Int, kotlin/Int): kotlin/Int // org.kotlincrypto.core.xof/Xof.Reader.read|read(kotlin.ByteArray;kotlin.Int;kotlin.Int){}[0]
         final fun toString(): kotlin/String // org.kotlincrypto.core.xof/Xof.Reader.toString|toString(){}[0]
+        final inline fun <#A2: kotlin/Any?> use(kotlin/Function1<org.kotlincrypto.core.xof/Xof.Reader<#A>, #A2>): #A2 // org.kotlincrypto.core.xof/Xof.Reader.use|use(kotlin.Function1<org.kotlincrypto.core.xof.Xof.Reader<2:0>,0:0>){0§<kotlin.Any?>}[0]
     }
 
     final object Companion { // org.kotlincrypto.core.xof/Xof.Companion|null[0]
diff --git a/library/xof/src/commonMain/kotlin/org/kotlincrypto/core/xof/Xof.kt b/library/xof/src/commonMain/kotlin/org/kotlincrypto/core/xof/Xof.kt
index f060fa9..2409f02 100644
--- a/library/xof/src/commonMain/kotlin/org/kotlincrypto/core/xof/Xof.kt
+++ b/library/xof/src/commonMain/kotlin/org/kotlincrypto/core/xof/Xof.kt
@@ -18,6 +18,9 @@
 package org.kotlincrypto.core.xof
 
 import org.kotlincrypto.core.*
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
 import kotlin.jvm.JvmField
 import kotlin.jvm.JvmName
 import kotlin.jvm.JvmOverloads
@@ -86,7 +89,16 @@ public sealed class Xof<A: XofAlgorithm>(
      *   initial state after taking the snapshot.
      * */
     @JvmOverloads
-    public fun <T: Any?> use(resetXof: Boolean = true, action: Reader.() -> T): T = reader(resetXof).use(action)
+    @OptIn(ExperimentalContracts::class)
+    public inline fun <T: Any?> use(
+        resetXof: Boolean = true,
+        action: Reader.() -> T,
+    ): T {
+        contract {
+            callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+        }
+        return reader(resetXof).use(action)
+    }
 
     /**
      * Takes a snapshot of the current [Xof]'s state and produces
@@ -145,9 +157,13 @@ public sealed class Xof<A: XofAlgorithm>(
          * Helper function which automatically invokes [close]
          * once action completes.
          * */
-        public fun <T: Any?> use(action: Reader.() -> T): T {
-            return try {
-                action(this)
+        @OptIn(ExperimentalContracts::class)
+        public inline fun <T: Any?> use(action: Reader.() -> T): T {
+            contract {
+                callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+            }
+            try {
+                return action(this)
             } finally {
                 close()
             }