diff --git a/ktor-server/ktor-server-test-suites/jvm/src/io/ktor/server/testing/suites/SustainabilityTestSuite.kt b/ktor-server/ktor-server-test-suites/jvm/src/io/ktor/server/testing/suites/SustainabilityTestSuite.kt
index bee995850bc..fafa55381d4 100644
--- a/ktor-server/ktor-server-test-suites/jvm/src/io/ktor/server/testing/suites/SustainabilityTestSuite.kt
+++ b/ktor-server/ktor-server-test-suites/jvm/src/io/ktor/server/testing/suites/SustainabilityTestSuite.kt
@@ -604,6 +604,7 @@ abstract class SustainabilityTestSuite<TEngine : ApplicationEngine, TConfigurati
         }
     }
 
+    @Ignore("Flaky. To be investigated in KTOR-7811")
     @Test
     @NoHttp2
     fun testHeaderIsTooLong() = runTest {