diff --git a/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/Selfie.kt b/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/Selfie.kt
index 993ec0a5..7d620e20 100644
--- a/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/Selfie.kt
+++ b/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/Selfie.kt
@@ -16,6 +16,7 @@
 package com.diffplug.selfie
 
 import com.diffplug.selfie.junit5.Router
+import org.junit.jupiter.api.Assertions.assertEquals
 import org.opentest4j.AssertionFailedError
 
 /**
@@ -68,8 +69,13 @@ class BinarySelfie(private val actual: ByteArray) : DiskSelfie(Snapshot.of(actua
 }
 fun expectSelfie(actual: ByteArray) = BinarySelfie(actual)
 
-class IntSelfie(private val actual: Int) {
-  fun toBe(expected: Int): Int = TODO()
+class IntSelfie(private val actual: Int) : DiskSelfie(Snapshot.of(actual.toString())) {
+  infix fun toBe(expected: Int): Int {
+    // TODO: Is this right?
+    val snapshot = toMatchDisk()
+    assertEquals(expected, snapshot.value.valueString().toInt())
+    return expected
+  }
   fun toBe_TODO(): Int = TODO()
 }
 fun expectSelfie(actual: Int) = IntSelfie(actual)
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/UT_IntSelfieTest.kt b/undertest-junit5/src/test/kotlin/undertest/junit5/UT_IntSelfieTest.kt
new file mode 100644
index 00000000..6a600a95
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/UT_IntSelfieTest.kt
@@ -0,0 +1,12 @@
+package undertest.junit5
+// spotless:off
+import com.diffplug.selfie.expectSelfie
+import kotlin.test.Test
+
+// spotless:on
+
+class UT_IntSelfieTest {
+  @Test fun singleInt() {
+    expectSelfie(678) toBe 678
+  }
+}
diff --git a/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_IntSelfieTest.ss b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_IntSelfieTest.ss
new file mode 100644
index 00000000..7e438d52
--- /dev/null
+++ b/undertest-junit5/src/test/kotlin/undertest/junit5/__snapshots__/UT_IntSelfieTest.ss
@@ -0,0 +1,3 @@
+╔═ singleInt ═╗
+678
+╔═ [end of file] ═╗