diff --git a/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieConfig.kt b/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieConfig.kt
index 719bb6da..d6f8a0be 100644
--- a/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieConfig.kt
+++ b/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieConfig.kt
@@ -22,7 +22,7 @@ import java.nio.file.Paths
 internal class SnapshotFileLayout(
     val rootFolder: Path,
     val snapshotFolderName: String?,
-    val unixNewlines: Boolean
+    internal val unixNewlines: Boolean
 ) {
   val extension: String = ".ss"
   fun snapshotPathForClass(className: String): Path {
@@ -75,14 +75,27 @@ internal class SnapshotFileLayout(
       val snapshotRootFolder = rootFolder(properties.getProperty("output-dir"))
       // it's pretty easy to preserve the line endings of existing snapshot files, but it's
       // a bit harder to create a fresh snapshot file with the correct line endings.
-      val cr =
-          snapshotRootFolder
-              .resolve(snapshotFolderName!!)
-              .toFile()
-              .walkTopDown()
-              .filter { it.isFile }
-              .any { it.readText().contains('\r') }
-      return SnapshotFileLayout(snapshotRootFolder, snapshotFolderName, !cr)
+      return SnapshotFileLayout(
+          snapshotRootFolder, snapshotFolderName, inferDefaultLineEndingIsUnix(snapshotRootFolder))
+    }
+    private fun inferDefaultLineEndingIsUnix(rootFolder: Path): Boolean {
+      return rootFolder
+          .toFile()
+          .walkTopDown()
+          .filter { it.isFile }
+          .mapNotNull {
+            try {
+              val txt = it.readText()
+              // look for a file that has a newline somewhere in it
+              if (txt.indexOf('\n') != -1) txt else null
+            } catch (e: Exception) {
+              // might be a binary file that throws an encoding exception
+              null
+            }
+          }
+          .firstOrNull()
+          ?.let { it.indexOf('\r') == -1 }
+          ?: true // if we didn't find any files, assume unix
     }
     private fun snapshotFolderName(snapshotDir: String?): String? {
       if (snapshotDir == null) {
diff --git a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/CarriageReturnTest.kt b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/CarriageReturnTest.kt
index 27d2f932..5091a315 100644
--- a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/CarriageReturnTest.kt
+++ b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/CarriageReturnTest.kt
@@ -63,9 +63,4 @@ class CarriageReturnTest : Harness("undertest-junit5") {
     gradleWriteSS()
     ut_snapshot().assertContent(expectedContent)
   }
-
-  @Test @Order(5)
-  fun deleteSelfie() {
-    ut_snapshot().deleteIfExists()
-  }
 }
diff --git a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/DuplicateWriteTest.kt b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/DuplicateWriteTest.kt
index d65dd3cc..3bc8a60d 100644
--- a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/DuplicateWriteTest.kt
+++ b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/DuplicateWriteTest.kt
@@ -62,9 +62,4 @@ class DuplicateWriteTest : Harness("undertest-junit5") {
     gradlew("underTest", "-Pselfie=writeonce")!!.message shouldStartWith
         "Snapshot was set to the same value multiple times"
   }
-
-  @Test @Order(6)
-  fun deleteSelfie() {
-    ut_snapshot().deleteIfExists()
-  }
 }
diff --git a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/ReadWriteTest.kt b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/ReadWriteTest.kt
index d6e047b6..c4a3f1ad 100644
--- a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/ReadWriteTest.kt
+++ b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/ReadWriteTest.kt
@@ -81,9 +81,4 @@ class ReadWriteTest : Harness("undertest-junit5") {
         """
                 .trimIndent())
   }
-
-  @Test @Order(6)
-  fun deleteSelfie() {
-    ut_snapshot().deleteIfExists()
-  }
 }
diff --git a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/WithinMethodGCTest.kt b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/WithinMethodGCTest.kt
index a7ccb84f..cafcbb27 100644
--- a/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/WithinMethodGCTest.kt
+++ b/selfie-runner-junit5/src/test/kotlin/com/diffplug/selfie/junit5/WithinMethodGCTest.kt
@@ -102,9 +102,4 @@ class WithinMethodGCTest : Harness("undertest-junit5") {
     ut_mirror().lineWith("selfie2()").commentOut()
     ut_mirror().lineWith("selfie()").uncomment()
   }
-
-  @Test @Order(7)
-  fun deleteSelfie() {
-    ut_snapshot().deleteIfExists()
-  }
 }
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/UT_WithinMethodGCTest.kt b/undertest-junit5/src/test/kotlin/undertest/junit5/UT_WithinMethodGCTest.kt
index cf8b7fbe..9a574547 100644
--- a/undertest-junit5/src/test/kotlin/undertest/junit5/UT_WithinMethodGCTest.kt
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/UT_WithinMethodGCTest.kt
@@ -1,4 +1,4 @@
-package com.diffplug.selfie.junit5
+package undertest.junit5
 // spotless:off
 import com.diffplug.selfie.expectSelfie
 import kotlin.test.Test
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_CarriageReturnTest.ss b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_CarriageReturnTest.ss
new file mode 100644
index 00000000..490e872b
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_CarriageReturnTest.ss
@@ -0,0 +1,7 @@
+╔═ git_makes_carriage_returns_unrepresentable ═╗
+hard
+to
+preserve
+this
+
+╔═ [end of file] ═╗
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_DuplicateWriteTest.ss b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_DuplicateWriteTest.ss
new file mode 100644
index 00000000..7debc001
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_DuplicateWriteTest.ss
@@ -0,0 +1,3 @@
+╔═ shouldPass ═╗
+twins
+╔═ [end of file] ═╗
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_ReadWriteTest.ss b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_ReadWriteTest.ss
new file mode 100644
index 00000000..4ca144c6
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_ReadWriteTest.ss
@@ -0,0 +1,3 @@
+╔═ selfie ═╗
+orange
+╔═ [end of file] ═╗
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_WithinMethodGCTest.ss b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_WithinMethodGCTest.ss
new file mode 100644
index 00000000..1dd2c432
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_WithinMethodGCTest.ss
@@ -0,0 +1,3 @@
+╔═ selfie2/leaf ═╗
+maple
+╔═ [end of file] ═╗