diff --git a/app/build.gradle b/app/build.gradle
index c605d177..e4548b2e 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -32,7 +32,7 @@ android {
     defaultConfig {
         minSdkVersion 23
         targetSdkVersion 33
-        versionCode 20
+        versionCode 21
         versionName "1.0.beta" + versionCode
 
         //TODO add resConfigs("en", "fr", "ja",...) ?
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index fb94897e..c0689c46 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -170,6 +170,10 @@
 -if interface * { @retrofit2.http.* <methods>; }
 -keep,allowobfuscation interface <1>
 
+# Keep inherited services.
+-if interface * { @retrofit2.http.* <methods>; }
+-keep,allowobfuscation interface * extends <1>
+
 # Keep generic signature of Call, Response (R8 full mode strips signatures from non-kept items).
 -keep,allowobfuscation,allowshrinking interface retrofit2.Call
 -keep,allowobfuscation,allowshrinking class retrofit2.Response
@@ -178,4 +182,6 @@
 # kept. Suspend functions are wrapped in continuations where the type argument
 # is used.
 -keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation
-##---------------End: proguard configuration for Retrofit  ----------
\ No newline at end of file
+##---------------End: proguard configuration for Retrofit  ----------
+
+-keep,allowobfuscation,allowshrinking class io.reactivex.rxjava3.core.Observable
\ No newline at end of file