diff --git a/src/test/kotlin/core/node/MockNode.kt b/src/test/kotlin/core/node/MockNode.kt
index c13fd97fa9..61279ab4fe 100644
--- a/src/test/kotlin/core/node/MockNode.kt
+++ b/src/test/kotlin/core/node/MockNode.kt
@@ -16,6 +16,7 @@
 
 package core.node
 
+import com.google.common.jimfs.Configuration
 import com.google.common.jimfs.Jimfs
 import com.google.common.util.concurrent.MoreExecutors
 import core.messaging.InMemoryMessagingNetwork
@@ -38,7 +39,7 @@ import java.util.concurrent.ExecutorService
  */
 class MockNetwork {
     private var counter = 0
-    val filesystem = Jimfs.newFileSystem()
+    val filesystem = Jimfs.newFileSystem(Configuration.unix())
     val messagingNetwork = InMemoryMessagingNetwork()
 
     private val _nodes = ArrayList<MockNode>()
diff --git a/src/test/kotlin/core/node/NodeAttachmentStorageTest.kt b/src/test/kotlin/core/node/NodeAttachmentStorageTest.kt
index b3c67f6d48..cea62c9614 100644
--- a/src/test/kotlin/core/node/NodeAttachmentStorageTest.kt
+++ b/src/test/kotlin/core/node/NodeAttachmentStorageTest.kt
@@ -8,6 +8,7 @@
 
 package core.node
 
+import com.google.common.jimfs.Configuration
 import com.google.common.jimfs.Jimfs
 import core.crypto.SecureHash
 import core.use
@@ -30,7 +31,7 @@ class NodeAttachmentStorageTest {
 
     @Before
     fun setUp() {
-        fs = Jimfs.newFileSystem()
+        fs = Jimfs.newFileSystem(Configuration.unix())
     }
 
     @Test