diff --git a/core/src/main/scala-2/caliban/schema/SchemaDerivation.scala b/core/src/main/scala-2/caliban/schema/SchemaDerivation.scala
index b7526f83a3..a138a556b7 100644
--- a/core/src/main/scala-2/caliban/schema/SchemaDerivation.scala
+++ b/core/src/main/scala-2/caliban/schema/SchemaDerivation.scala
@@ -76,7 +76,7 @@ trait CommonSchemaDerivation[R] {
                 getName(p),
                 getDescription(p),
                 () =>
-                  if (p.typeclass.optional || p.typeclass.canFail) p.typeclass.toType_(isInput, isSubscription)
+                  if (p.typeclass.optional) p.typeclass.toType_(isInput, isSubscription)
                   else p.typeclass.toType_(isInput, isSubscription).nonNull,
                 p.annotations.collectFirst { case GQLDefault(v) => v },
                 p.annotations.collectFirst { case GQLDeprecated(_) => () }.isDefined,
@@ -98,7 +98,7 @@ trait CommonSchemaDerivation[R] {
               val (isNullable, isNullabilityForced) = {
                 val hasNullableAnn = p.annotations.contains(GQLNullable())
                 val hasNonNullAnn  = p.annotations.contains(GQLNonNullable())
-                (!hasNonNullAnn && (hasNullableAnn || p.typeclass.optional), hasNullableAnn || hasNonNullAnn)
+                (!hasNonNullAnn && (hasNullableAnn || p.typeclass.nullable), hasNullableAnn || hasNonNullAnn)
               }
               Types.makeField(
                 getName(p),
diff --git a/core/src/main/scala-3/caliban/schema/DerivationUtils.scala b/core/src/main/scala-3/caliban/schema/DerivationUtils.scala
index 040b327b65..853c26ca2c 100644
--- a/core/src/main/scala-3/caliban/schema/DerivationUtils.scala
+++ b/core/src/main/scala-3/caliban/schema/DerivationUtils.scala
@@ -105,7 +105,7 @@ private object DerivationUtils {
         name,
         getDescription(fieldAnnotations),
         () =>
-          if (schema.optional || schema.canFail) schema.toType_(isInput, isSubscription)
+          if (schema.optional) schema.toType_(isInput, isSubscription)
           else schema.toType_(isInput, isSubscription).nonNull,
         getDefaultValue(fieldAnnotations),
         getDeprecatedReason(fieldAnnotations).isDefined,
@@ -130,7 +130,7 @@ private object DerivationUtils {
       val (isNullable, isNullabilityForced) = {
         val hasNullableAnn = fieldAnnotations.contains(GQLNullable())
         val hasNonNullAnn  = fieldAnnotations.contains(GQLNonNullable())
-        (!hasNonNullAnn && (hasNullableAnn || schema.optional), hasNullableAnn || hasNonNullAnn)
+        (!hasNonNullAnn && (hasNullableAnn || schema.nullable), hasNullableAnn || hasNonNullAnn)
       }
       Types.makeField(
         name,
diff --git a/core/src/main/scala/caliban/schema/Schema.scala b/core/src/main/scala/caliban/schema/Schema.scala
index b5001c5bf3..069e401948 100644
--- a/core/src/main/scala/caliban/schema/Schema.scala
+++ b/core/src/main/scala/caliban/schema/Schema.scala
@@ -73,9 +73,16 @@ trait Schema[-R, T] { self =>
   def resolve(value: T): Step[R]
 
   /**
-   * Defines if the type is considered optional or non-null. Should be false except for `Option`.
+   * Defines if the type can resolve to null or not.
+   * It is true if the type is nullable or if it can fail.
    */
-  def optional: Boolean = false
+  @deprecatedOverriding("this method will be made final. Override canFail and nullable instead", "2.6.1")
+  def optional: Boolean = canFail || nullable
+
+  /**
+   * Defines if the underlying type represents a nullable value. Should be false except for `Option`.
+   */
+  def nullable: Boolean = false
 
   /**
    * Defines if the type can fail during resolution.
@@ -95,7 +102,7 @@ trait Schema[-R, T] { self =>
    * @param f a function from `A` to `T`.
    */
   def contramap[A](f: A => T): Schema[R, A] = new Schema[R, A] {
-    override def optional: Boolean                                         = self.optional
+    override def nullable: Boolean                                         = self.nullable
     override def canFail: Boolean                                          = self.canFail
     override def arguments: List[__InputValue]                             = self.arguments
     override def toType(isInput: Boolean, isSubscription: Boolean): __Type = self.toType_(isInput, isSubscription)
@@ -108,7 +115,7 @@ trait Schema[-R, T] { self =>
    * @param inputName new name for the type when it's an input type (by default "Input" is added after the name)
    */
   def rename(name: String, inputName: Option[String] = None): Schema[R, T] = new Schema[R, T] {
-    override def optional: Boolean                                         = self.optional
+    override def nullable: Boolean                                         = self.nullable
     override def canFail: Boolean                                          = self.canFail
     override def arguments: List[__InputValue]                             = self.arguments
     override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
@@ -347,7 +354,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     Schema.stringSchema.contramap(Cursor[Base64Cursor].encode)
 
   implicit def optionSchema[R0, A](implicit ev: Schema[R0, A]): Schema[R0, Option[A]]                                  = new Schema[R0, Option[A]] {
-    override def optional: Boolean                                         = true
+    override def nullable: Boolean                                         = true
     override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
 
     override def resolve(value: Option[A]): Step[R0] =
@@ -359,7 +366,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
   implicit def listSchema[R0, A](implicit ev: Schema[R0, A]): Schema[R0, List[A]]                                      = new Schema[R0, List[A]] {
     override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
       val t = ev.toType_(isInput, isSubscription)
-      (if (ev.optional || ev.canFail) t else t.nonNull).list
+      (if (ev.nullable || ev.canFail) t else t.nonNull).list
     }
 
     override def resolve(value: List[A]): Step[R0] = ListStep(value.map(ev.resolve))
@@ -372,7 +379,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     listSchema[R0, A].contramap(_.toList)
   implicit def functionUnitSchema[R0, A](implicit ev: Schema[R0, A]): Schema[R0, () => A]                              =
     new Schema[R0, () => A] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = ev.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: () => A): Step[R0]                         = FunctionStep(_ => ev.resolve(value()))
@@ -380,7 +387,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
   implicit def metadataFunctionSchema[R0, A](implicit ev: Schema[R0, A]): Schema[R0, Field => A]                       =
     new Schema[R0, Field => A] {
       override def arguments: List[__InputValue]                             = ev.arguments
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = ev.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: Field => A): Step[R0]                      = MetadataFunctionStep(field => ev.resolve(value(field)))
@@ -396,13 +403,13 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     val description: String = s"Either $typeAName or $typeBName"
 
     implicit val leftSchema: Schema[RA, A]  = new Schema[RA, A] {
-      override def optional: Boolean                                         = true
+      override def nullable: Boolean                                         = true
       override def canFail: Boolean                                          = evA.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = evA.toType_(isInput, isSubscription)
       override def resolve(value: A): Step[RA]                               = evA.resolve(value)
     }
     implicit val rightSchema: Schema[RB, B] = new Schema[RB, B] {
-      override def optional: Boolean                                         = true
+      override def nullable: Boolean                                         = true
       override def canFail: Boolean                                          = evB.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = evB.toType_(isInput, isSubscription)
       override def resolve(value: B): Step[RB]                               = evB.resolve(value)
@@ -471,14 +478,14 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
               __InputValue(
                 unwrappedArgumentName,
                 None,
-                () => if (ev1.optional || ev1.canFail) inputType else inputType.nonNull,
+                () => if (ev1.nullable || ev1.canFail) inputType else inputType.nonNull,
                 None
               )
             )
           )
       }
 
-      override def optional: Boolean                                         = ev2.optional
+      override def nullable: Boolean                                         = ev2.nullable
       override def canFail: Boolean                                          = ev2.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev2.toType_(isInput, isSubscription)
 
@@ -507,7 +514,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     effectSchema[R0, R0, R0, Throwable, A].contramap[Future[A]](future => ZIO.fromFuture(_ => future)(Trace.empty))
   implicit def infallibleEffectSchema[R0, R1 >: R0, R2 >: R0, A](implicit ev: Schema[R2, A]): Schema[R0, URIO[R1, A]] =
     new Schema[R0, URIO[R1, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = ev.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: URIO[R1, A]): Step[R0]                     = QueryStep(ZQuery.fromZIONow(value.map(ev.resolve)))
@@ -516,7 +523,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZIO[R1, E, A]] =
     new Schema[R0, ZIO[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: ZIO[R1, E, A]): Step[R0]                   = QueryStep(ZQuery.fromZIONow(value.map(ev.resolve)))
@@ -525,7 +532,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZIO[R1, E, A]] =
     new Schema[R0, ZIO[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: ZIO[R1, E, A]): Step[R0]                   = QueryStep(
@@ -536,7 +543,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZQuery[R1, Nothing, A]] =
     new Schema[R0, ZQuery[R1, Nothing, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = ev.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: ZQuery[R1, Nothing, A]): Step[R0]          = QueryStep(value.map(ev.resolve))
@@ -545,7 +552,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZQuery[R1, E, A]] =
     new Schema[R0, ZQuery[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: ZQuery[R1, E, A]): Step[R0]                = QueryStep(value.map(ev.resolve))
@@ -554,7 +561,7 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZQuery[R1, E, A]] =
     new Schema[R0, ZQuery[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
       override def resolve(value: ZQuery[R1, E, A]): Step[R0]                = QueryStep(value.mapBoth(convertError, ev.resolve))
@@ -563,11 +570,11 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R1, ZStream[R1, Nothing, A]] =
     new Schema[R1, ZStream[R1, Nothing, A]] {
-      override def optional: Boolean                                         = false
+      override def nullable: Boolean                                         = false
       override def canFail: Boolean                                          = ev.canFail
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
         val t = ev.toType_(isInput, isSubscription)
-        if (isSubscription) t else (if (ev.optional || ev.canFail) t else t.nonNull).list
+        if (isSubscription) t else (if (ev.nullable || ev.canFail) t else t.nonNull).list
       }
       override def resolve(value: ZStream[R1, Nothing, A]): Step[R1]         = StreamStep(value.map(ev.resolve))
     }
@@ -575,11 +582,11 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZStream[R1, E, A]] =
     new Schema[R0, ZStream[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
         val t = ev.toType_(isInput, isSubscription)
-        if (isSubscription) t else (if (ev.optional || ev.canFail) t else t.nonNull).list
+        if (isSubscription) t else (if (ev.nullable || ev.canFail) t else t.nonNull).list
       }
       override def resolve(value: ZStream[R1, E, A]): Step[R0]               = StreamStep(value.map(ev.resolve))
     }
@@ -587,11 +594,11 @@ trait GenericSchema[R] extends SchemaDerivation[R] with TemporalSchema {
     ev: Schema[R2, A]
   ): Schema[R0, ZStream[R1, E, A]] =
     new Schema[R0, ZStream[R1, E, A]] {
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
         val t = ev.toType_(isInput, isSubscription)
-        if (isSubscription) t else (if (ev.optional || ev.canFail) t else t.nonNull).list
+        if (isSubscription) t else (if (ev.nullable || ev.canFail) t else t.nonNull).list
       }
       override def resolve(value: ZStream[R1, E, A]): Step[R0]               = StreamStep(value.mapBoth(convertError, ev.resolve))
     }
@@ -724,7 +731,7 @@ abstract class PartiallyAppliedFieldBase[V](
       description,
       _ => Nil,
       () =>
-        if (ev.optional || ev.canFail) ev.toType_(ft.isInput, ft.isSubscription)
+        if (ev.nullable || ev.canFail) ev.toType_(ft.isInput, ft.isSubscription)
         else ev.toType_(ft.isInput, ft.isSubscription).nonNull,
       isDeprecated = Directives.isDeprecated(directives),
       deprecationReason = Directives.deprecationReason(directives),
@@ -768,7 +775,7 @@ case class PartiallyAppliedFieldWithArgs[V, A](
         description,
         ev1.arguments,
         () =>
-          if (ev1.optional || ev1.canFail) ev1.toType_(fa.isInput, fa.isSubscription)
+          if (ev1.nullable || ev1.canFail) ev1.toType_(fa.isInput, fa.isSubscription)
           else ev1.toType_(fa.isInput, fa.isSubscription).nonNull,
         isDeprecated = Directives.isDeprecated(directives),
         deprecationReason = Directives.deprecationReason(directives),
diff --git a/core/src/test/scala/caliban/TriState.scala b/core/src/test/scala/caliban/TriState.scala
index 2e9646587d..f6ae618f00 100644
--- a/core/src/test/scala/caliban/TriState.scala
+++ b/core/src/test/scala/caliban/TriState.scala
@@ -15,7 +15,7 @@ object TriState {
 
   def schemaCustom[R, A](undefined: PureStep)(implicit ev: Schema[R, A]): Schema[R, TriState[A]] =
     new Schema[R, TriState[A]] {
-      override val optional = true
+      override val nullable = true
 
       override def toType(isInput: Boolean, isSubscription: Boolean) = ev.toType_(isInput, isSubscription)
 
diff --git a/federation/src/main/scala/caliban/federation/FederationSupport.scala b/federation/src/main/scala/caliban/federation/FederationSupport.scala
index 5eef75a02c..e4d695f94c 100644
--- a/federation/src/main/scala/caliban/federation/FederationSupport.scala
+++ b/federation/src/main/scala/caliban/federation/FederationSupport.scala
@@ -60,7 +60,7 @@ abstract class FederationSupport(
     import genericSchema.auto._
 
     implicit val entitySchema: Schema[R, _Entity] = new Schema[R, _Entity] {
-      override def optional: Boolean                                         = true
+      override def nullable: Boolean                                         = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type =
         __Type(
           __TypeKind.UNION,
diff --git a/interop/cats/src/main/scala/caliban/interop/cats/CatsInterop.scala b/interop/cats/src/main/scala/caliban/interop/cats/CatsInterop.scala
index f387813a68..4883479881 100644
--- a/interop/cats/src/main/scala/caliban/interop/cats/CatsInterop.scala
+++ b/interop/cats/src/main/scala/caliban/interop/cats/CatsInterop.scala
@@ -190,8 +190,8 @@ object CatsInterop {
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type =
         ev.toType_(isInput, isSubscription)
 
-      override def optional: Boolean =
-        ev.optional
+      override def nullable: Boolean =
+        ev.nullable
       override def canFail: Boolean  = true
 
       override def resolve(value: F[A]): Step[R] =
diff --git a/interop/cats/src/main/scala/caliban/interop/fs2/Fs2Interop.scala b/interop/cats/src/main/scala/caliban/interop/fs2/Fs2Interop.scala
index 5c6e8f0c92..c2a3239f2a 100644
--- a/interop/cats/src/main/scala/caliban/interop/fs2/Fs2Interop.scala
+++ b/interop/cats/src/main/scala/caliban/interop/fs2/Fs2Interop.scala
@@ -14,7 +14,7 @@ object Fs2Interop {
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type =
         ev.toType_(isInput, isSubscription)
 
-      override def optional: Boolean = ev.optional
+      override def nullable: Boolean = ev.nullable
       override def canFail: Boolean  = true
 
       override def resolve(value: Stream[RIO[R, *], A]): Step[R] =
@@ -29,7 +29,7 @@ object Fs2Interop {
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type =
         ev.toType_(isInput, isSubscription)
 
-      override def optional: Boolean = ev.optional
+      override def nullable: Boolean = ev.nullable
       override def canFail: Boolean  = true
 
       override def resolve(value: Stream[F, A]): Step[R] =
diff --git a/interop/monix/src/main/scala/caliban/interop/monix/MonixInterop.scala b/interop/monix/src/main/scala/caliban/interop/monix/MonixInterop.scala
index daf648929d..c29e38e8e1 100644
--- a/interop/monix/src/main/scala/caliban/interop/monix/MonixInterop.scala
+++ b/interop/monix/src/main/scala/caliban/interop/monix/MonixInterop.scala
@@ -60,7 +60,7 @@ object MonixInterop {
   def taskSchema[R, A](implicit ev: Schema[R, A], ev2: ConcurrentEffect[MonixTask]): Schema[R, MonixTask[A]] =
     new Schema[R, MonixTask[A]] {
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = ev.toType_(isInput, isSubscription)
-      override def optional: Boolean                                         = ev.optional
+      override def nullable: Boolean                                         = ev.nullable
       override def canFail: Boolean                                          = true
       override def resolve(value: MonixTask[A]): Step[R]                     =
         QueryStep(ZQuery.fromZIO(value.to[Task].map(ev.resolve)))
@@ -70,10 +70,10 @@ object MonixInterop {
     queueSize: Int
   )(implicit ev: Schema[R, A], ev2: ConcurrentEffect[MonixTask]): Schema[R, Observable[A]] =
     new Schema[R, Observable[A]] {
-      override def optional: Boolean                                         = true
+      override def nullable: Boolean                                         = true
       override def toType(isInput: Boolean, isSubscription: Boolean): __Type = {
         val t = ev.toType_(isInput, isSubscription)
-        if (isSubscription) t else (if (ev.optional) t else t.nonNull).list
+        if (isSubscription) t else (if (ev.nullable) t else t.nonNull).list
       }
       override def resolve(value: Observable[A]): Step[R]                    =
         StreamStep(
diff --git a/interop/tapir/src/main/scala/caliban/interop/tapir/package.scala b/interop/tapir/src/main/scala/caliban/interop/tapir/package.scala
index 00ef144aee..b7e92669b7 100644
--- a/interop/tapir/src/main/scala/caliban/interop/tapir/package.scala
+++ b/interop/tapir/src/main/scala/caliban/interop/tapir/package.scala
@@ -106,7 +106,7 @@ package object tapir {
             Types.makeField(
               extractPath(serverEndpoint.endpoint.info.name, serverEndpoint.endpoint.input),
               serverEndpoint.endpoint.info.description,
-              getArgs(inputSchema.toType_(isInput = true), inputSchema.optional || inputSchema.canFail),
+              getArgs(inputSchema.toType_(isInput = true), inputSchema.optional),
               () =>
                 if (serverEndpoint.endpoint.errorOutput == EndpointOutput.Void[E]())
                   outputSchema.toType_().nonNull