diff --git a/oeffi/build.gradle b/oeffi/build.gradle
index fd99b25..47e7cf5 100644
--- a/oeffi/build.gradle
+++ b/oeffi/build.gradle
@@ -25,7 +25,7 @@ dependencies {
     implementation 'com.squareup.okhttp3:logging-interceptor:3.12.13'
     implementation 'com.google.guava:guava:31.1-android'
     implementation 'org.osmdroid:osmdroid-android:6.1.14'
-    implementation 'org.slf4j:slf4j-api:1.7.36'
+    implementation 'org.slf4j:slf4j-api:2.0.7'
     implementation 'com.github.tony19:logback-android:3.0.0'
     testImplementation 'junit:junit:4.13.2'
 }
diff --git a/oeffi/proguard.cfg b/oeffi/proguard.cfg
index 0c6bf6f..1566d6d 100644
--- a/oeffi/proguard.cfg
+++ b/oeffi/proguard.cfg
@@ -78,12 +78,8 @@
 -dontnote com.google.common.util.concurrent.AbstractFuture$UnsafeAtomicHelper
 -dontnote dalvik.system.CloseGuard
 
-# slf4j
--dontwarn org.slf4j.spi.SLF4JServiceProvider
--dontwarn org.slf4j.LoggerFactory
--dontwarn ch.qos.logback.classic.Logger
-
-# logback-android
+# SLF4J, logback-android
+-keep class org.slf4j.impl.LoggerServiceProvider
 -dontwarn javax.mail.**
 -dontnote ch.qos.logback.core.android.AndroidContextUtil