diff --git a/webapi/src/main/scala/org/knora/webapi/slice/admin/domain/model/KnoraGroup.scala b/webapi/src/main/scala/org/knora/webapi/slice/admin/domain/model/KnoraGroup.scala
index 0ecdc83cdd..ff3d74ebf4 100644
--- a/webapi/src/main/scala/org/knora/webapi/slice/admin/domain/model/KnoraGroup.scala
+++ b/webapi/src/main/scala/org/knora/webapi/slice/admin/domain/model/KnoraGroup.scala
@@ -11,7 +11,6 @@ import sttp.tapir.CodecFormat
 import zio.Chunk
 import zio.json.DeriveJsonCodec
 import zio.json.JsonCodec
-
 import dsp.valueobjects.Iri
 import dsp.valueobjects.UuidUtil
 import org.knora.webapi.IRI
@@ -103,9 +102,10 @@ object GroupIri extends StringValueCompanion[GroupIri] {
   private def isBuiltInGroupIri(iri: String): Boolean = BuiltInGroups.contains(iri)
 
   def from(value: String): Either[String, GroupIri] = value match {
-    case _ if value.isEmpty          => Left("Group IRI cannot be empty.")
-    case _ if isGroupIriValid(value) => Right(GroupIri(value))
-    case v                           => Left(s"Group IRI is invalid: $v")
+    case _ if value.isEmpty                    => Left("Group IRI cannot be empty.")
+    case _ if value.startsWith("knora-admin:") => from(value.replace("knora-admin:", KnoraAdminPrefixExpansion))
+    case _ if isGroupIriValid(value)           => Right(GroupIri(value))
+    case v                                     => Left(s"Group IRI is invalid: $v")
   }
 
   /**
diff --git a/webapi/src/test/scala/org/knora/webapi/slice/admin/domain/model/GroupIriSpec.scala b/webapi/src/test/scala/org/knora/webapi/slice/admin/domain/model/GroupIriSpec.scala
index 1e145981a3..940ee6121f 100644
--- a/webapi/src/test/scala/org/knora/webapi/slice/admin/domain/model/GroupIriSpec.scala
+++ b/webapi/src/test/scala/org/knora/webapi/slice/admin/domain/model/GroupIriSpec.scala
@@ -5,6 +5,8 @@
 
 package org.knora.webapi.slice.admin.domain.model
 
+import org.knora.webapi.messages.OntologyConstants.KnoraAdmin.KnoraAdminPrefixExpansion
+import zio.Chunk
 import zio.test.Gen
 import zio.test.Spec
 import zio.test.ZIOSpecDefault
@@ -16,6 +18,13 @@ object GroupIriSpec extends ZIOSpecDefault {
     test("not be created from an empty value") {
       assertTrue(GroupIri.from("") == Left("Group IRI cannot be empty."))
     },
+    test("allow prefixed builtin GroupIris") {
+      val builtIn = Chunk("UnknownUser", "KnownUser", "Creator", "ProjectMember", "ProjectAdmin", "SystemAdmin")
+        .map("knora-admin:" + _)
+      check(Gen.fromIterable(builtIn)) { it =>
+        assertTrue(GroupIri.from(it).map(_.value) == Right(it.replace("knora-admin:", KnoraAdminPrefixExpansion)))
+      }
+    },
     test("be created from a valid value") {
       val validIris = Gen.fromIterable(
         Seq(