diff --git a/playtest-http/src/main/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxy.kt b/playtest-http/src/main/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxy.kt
index 2f8d005..b7a0e71 100644
--- a/playtest-http/src/main/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxy.kt
+++ b/playtest-http/src/main/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxy.kt
@@ -11,19 +11,23 @@ class ResponseBodyProxy private constructor(val body: Path) : ShouldBeString, Sh
     }
 
     // FIXME need more explained
-    override fun shouldBe(expected: String): TestResult =
-        if (body.toFile().readText(Charsets.UTF_8) == expected) {
+    override fun shouldBe(expected: String): TestResult {
+        val actual = body.toFile().readText(Charsets.UTF_8)
+        return if (actual == expected) {
             Ok
         } else {
-            Failed { simpleExplain(expected, body) }
+            Failed { simpleExplain(expected, actual) }
         }
+    }
 
-    override fun shouldContain(expected: String): TestResult =
-        if (body.toFile().readText(Charsets.UTF_8).contains(expected)) {
+    override fun shouldContain(expected: String): TestResult {
+        val actual = body.toFile().readText(Charsets.UTF_8)
+        return if (actual.contains(expected)) {
             Ok
         } else {
-            Failed { simpleExplain(expected, body) }
+            Failed { simpleExplain(expected, actual) }
         }
+    }
 
     override fun toJsonPathProxy(path: String): JsonPathProxy =
         body.toFile().readText(Charsets.UTF_8)
diff --git a/playtest-http/src/test/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxyTest.kt b/playtest-http/src/test/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxyTest.kt
index d912f94..dba1104 100644
--- a/playtest-http/src/test/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxyTest.kt
+++ b/playtest-http/src/test/kotlin/com/uzabase/playtest2/http/proxy/ResponseBodyProxyTest.kt
@@ -37,8 +37,8 @@ class ResponseBodyProxyTest : FunSpec({
                 |  value: Hello, world!!
                 |  class: kotlin.String
                 |Actual:
-                |  value: [^\s]+/com/uzabase/playtest2/http/proxy/response-body.txt
-                |  class: sun.nio.fs.UnixPath
+                |  value: Hello, world
+                |  class: kotlin.String
                 """.trimMargin()
             )
         }
@@ -50,9 +50,19 @@ class ResponseBodyProxyTest : FunSpec({
         }
 
         test("should not contain") {
-            fromClasspathToResponseBodyProxy("com/uzabase/playtest2/http/proxy/response-body.txt")
+            val result = fromClasspathToResponseBodyProxy("com/uzabase/playtest2/http/proxy/response-body.txt")
                 .shouldContain("world!!")
-                .shouldBeInstanceOf<Failed>()
+            result.shouldBeInstanceOf<Failed>()
+            result.explain().shouldMatch(
+                """
+                |Expected:
+                |  value: world!!
+                |  class: kotlin.String
+                |Actual:
+                |  value: Hello, world
+                |  class: kotlin.String
+                """.trimMargin()
+            )
         }
     }