diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 190569aa8..133647df8 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -34,3 +34,7 @@
 -keep,allowobfuscation,allowshrinking class com.google.gson.reflect.TypeToken
 -keep,allowobfuscation,allowshrinking class * extends com.google.gson.reflect.TypeToken
 
+# Some prettytime stuff
+-keep class com.ocpsoft.pretty.time.i18n.**
+-keep class org.ocpsoft.prettytime.i18n.**
+-keepnames class ** implements org.ocpsoft.prettytime.TimeUnit