diff --git a/deltachat-ffi/deltachat.h b/deltachat-ffi/deltachat.h
index 4e8b307d8..634eab881 100644
--- a/deltachat-ffi/deltachat.h
+++ b/deltachat-ffi/deltachat.h
@@ -1587,11 +1587,11 @@ int             dc_set_chat_profile_image    (dc_context_t* context, uint32_t ch
  *
  * @memberof dc_context_t
  * @param chat_id The chat ID to set the mute duration.
- * @param duration The duration (0 for no mute, -1 for forever mute, >0 unix timestamp it until it should be unmuted again)
+ * @param duration The duration (0 for no mute, -1 for forever mute, everything else is is the relative mute duration from now in seconds)
  * @param context The context as created by dc_context_new().
  * @return 1=success, 0=error
  */
-int             dc_set_chat_muted             (dc_context_t* context, uint32_t chat_id, int64_t duration);
+int             dc_chat_set_mute_duration             (dc_context_t* context, uint32_t chat_id, int64_t duration);
 
 // handle messages
 
@@ -2950,7 +2950,7 @@ int             dc_chat_is_muted (const dc_chat_t* chat);
  *
  * @memberof dc_chat_t
  * @param chat The chat object.
- * @return 0=not muted, -1=forever muted, (x>0)=unix timestamp until mute is lifted
+ * @return 0=not muted, -1=forever muted, (x>0)=remaining seconds until the mute is lifted
  */
 int64_t          dc_chat_get_mute_duration (const dc_chat_t* chat);
 
diff --git a/deltachat-ffi/src/lib.rs b/deltachat-ffi/src/lib.rs
index 4be954a9e..ae69b3a28 100644
--- a/deltachat-ffi/src/lib.rs
+++ b/deltachat-ffi/src/lib.rs
@@ -25,6 +25,7 @@ use libc::uintptr_t;
 use num_traits::{FromPrimitive, ToPrimitive};
 
 use deltachat::chat::ChatId;
+use deltachat::chat::MuteDuration;
 use deltachat::constants::DC_MSG_ID_LAST_SPECIAL;
 use deltachat::contact::Contact;
 use deltachat::context::Context;
@@ -33,6 +34,9 @@ use deltachat::message::MsgId;
 use deltachat::stock::StockMessage;
 use deltachat::*;
 
+mod tools;
+use crate::tools::time;
+
 mod dc_array;
 
 mod string;
@@ -1408,19 +1412,26 @@ pub unsafe extern "C" fn dc_set_chat_profile_image(
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn dc_set_chat_muted(
+pub unsafe extern "C" fn dc_chat_set_mute_duration(
     context: *mut dc_context_t,
     chat_id: u32,
     duration: i64,
 ) -> libc::c_int {
     if context.is_null() || chat_id <= constants::DC_CHAT_ID_LAST_SPECIAL as u32 {
-        eprintln!("ignoring careless call to dc_set_chat_muted()");
+        eprintln!("ignoring careless call to dc_chat_set_mute_duration()");
         return 0;
     }
+
+    let muteDuration = match duration {
+        0 => MuteDuration::NotMuted,
+        -1 => MuteDuration::Forever,
+        _ => MuteDuration::MutedUntilTimestamp(time() + duration),
+    };
+
     let ffi_context = &*context;
     ffi_context
         .with_inner(|ctx| {
-            chat::set_muted(ctx, chat_id, chat::MuteDuration::deserialize(duration))
+            chat::set_muted(ctx, chat_id, muteDuration)
                 .map(|_| 1)
                 .unwrap_or_log_default(ctx, "Failed to set mute duration")
         })
@@ -2514,11 +2525,18 @@ pub unsafe extern "C" fn dc_chat_is_muted(chat: *mut dc_chat_t) -> libc::c_int {
 #[no_mangle]
 pub unsafe extern "C" fn dc_chat_get_mute_duration(chat: *mut dc_chat_t) -> i64 {
     if chat.is_null() {
-        eprintln!("ignoring careless call to dc_chat_is_muted()");
+        eprintln!("ignoring careless call to dc_chat_get_mute_duration()");
         return 0;
     }
     let ffi_chat = &*chat;
-    ffi_chat.chat.mute_duration.serialize() as i64
+    if !ffi_chat.chat.is_muted() {
+        return 0;
+    }
+    match ffi_chat.chat.mute_duration {
+        MuteDuration::NotMuted => 0,
+        MuteDuration::Forever => -1,
+        MuteDuration::MutedUntilTimestamp(timestamp) => timestamp - time(),
+    }
 }
 
 #[no_mangle]
diff --git a/deltachat-ffi/src/tools.rs b/deltachat-ffi/src/tools.rs
new file mode 100644
index 000000000..e7f7e8bb7
--- /dev/null
+++ b/deltachat-ffi/src/tools.rs
@@ -0,0 +1,8 @@
+use std::time::SystemTime;
+
+pub(crate) fn time() -> i64 {
+    SystemTime::now()
+        .duration_since(SystemTime::UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs() as i64
+}
diff --git a/python/src/deltachat/chat.py b/python/src/deltachat/chat.py
index 525c358f0..0b5ff3e40 100644
--- a/python/src/deltachat/chat.py
+++ b/python/src/deltachat/chat.py
@@ -105,20 +105,20 @@ class Chat(object):
         :returns: 
         """
         if duration is None:
-            timestamp = -1
+            mute_duration = -1
         else:
-            timestamp = int(time.time()) + duration
-        return bool(lib.dc_set_chat_muted(self._dc_context, self.id, timestamp))
+            mute_duration = duration
+        return bool(lib.dc_chat_set_mute_duration(self._dc_context, self.id, mute_duration))
 
     def unmute(self):
         """ unmutes the chat
 
         :returns: 
         """
-        return bool(lib.dc_set_chat_muted(self._dc_context, self.id, 0))
+        return bool(lib.dc_chat_set_mute_duration(self._dc_context, self.id, 0))
 
     def get_mute_duration(self):
-        """ mutes the chat
+        """ Returns the number of seconds until the mute of this chat is lifted.
 
         :param duration: 
         :returns: Returns the number of seconds the chat is still muted for. (0 for not muted, -1 forever muted)
diff --git a/src/chat.rs b/src/chat.rs
index 741f7627e..a1abb68dc 100644
--- a/src/chat.rs
+++ b/src/chat.rs
@@ -1938,7 +1938,13 @@ impl MuteDuration {
         match value {
             0 => MuteDuration::NotMuted,
             -1 => MuteDuration::Forever,
-            _ => MuteDuration::MutedUntilTimestamp(value),
+            _ => {
+                if value <= time() {
+                    MuteDuration::NotMuted
+                } else {
+                    MuteDuration::MutedUntilTimestamp(value)
+                }
+            }
         }
     }
 }