diff --git a/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/GafferConfiguratorEx.groovy b/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/GafferConfiguratorEx.groovy
index d07aced60..a5c585d04 100644
--- a/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/GafferConfiguratorEx.groovy
+++ b/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/GafferConfiguratorEx.groovy
@@ -24,6 +24,8 @@ import org.codehaus.groovy.control.CompilerConfiguration
  *
  * @author akhikhl
  */
+// FIXME #162 recent logback versions do not include GafferConfigurator
+// see also: remark in Runner.groovy, the only call site
 @CompileStatic(TypeCheckingMode.SKIP)
 class GafferConfiguratorEx extends GafferConfigurator {
 
diff --git a/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/Runner.groovy b/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/Runner.groovy
index 81c39fea0..f38295031 100644
--- a/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/Runner.groovy
+++ b/libs/gretty-runner/src/main/groovy/org/akhikhl/gretty/Runner.groovy
@@ -80,7 +80,10 @@ final class Runner {
     binding.logFileName = serverParams.logFileName
     binding.logDir = serverParams.logDir
     binding.grettyDebug = params.debug
-    new GafferConfiguratorEx(logCtx).run(binding, logbackConfigText)
+    // FIXME #162 logback has temporarily suspended GafferConfigurator.
+    // We do not know if and when it will come back, see news of 2019-10-11:
+    // http://logback.qos.ch/news.html
+    // new GafferConfiguratorEx(logCtx).run(binding, logbackConfigText)
   }
 
   private static Level stringToLoggingLevel(String str) {
diff --git a/libs/gretty/src/main/groovy/org/akhikhl/gretty/ServletContainerConfig.groovy b/libs/gretty/src/main/groovy/org/akhikhl/gretty/ServletContainerConfig.groovy
index 5dff6878b..541be8695 100644
--- a/libs/gretty/src/main/groovy/org/akhikhl/gretty/ServletContainerConfig.groovy
+++ b/libs/gretty/src/main/groovy/org/akhikhl/gretty/ServletContainerConfig.groovy
@@ -71,6 +71,10 @@ class ServletContainerConfig {
           def asm_version = project.ext.asmVersion
           force "org.ow2.asm:asm:$asm_version"
           force "org.ow2.asm:asm-commons:$asm_version"
+
+          // FIXME #162 make Tomcat and Jetty agree on a common version of logback again?
+          force 'ch.qos.logback:logback-classic:1.3.0-alpha5'
+          force 'org.slf4j:slf4j-api:2.0.0-alpha1'
         }
       },
       servletApiVersion: { project -> project.ext.jetty11ServletApiVersion },