diff --git a/src/dc_chat.rs b/src/dc_chat.rs
index 0bd8ad03e..72f3824c9 100644
--- a/src/dc_chat.rs
+++ b/src/dc_chat.rs
@@ -426,24 +426,17 @@ unsafe fn prepare_msg_common<'a>(
                 Typical conversions:
                 - from FILE to AUDIO/VIDEO/IMAGE
                 - from FILE/IMAGE to GIF */
-                let mut better_type = Viewtype::Unknown;
-                let mut better_mime = std::ptr::null_mut();
 
-                dc_msg_guess_msgtype_from_suffix(pathNfilename, &mut better_type, &mut better_mime);
-                if Viewtype::Unknown != better_type && !better_mime.is_null() {
-                    (*msg).type_0 = better_type;
-                    (*msg).param.set(Param::MimeType, as_str(better_mime));
+                if let Some((type_, mime)) =
+                    dc_msg_guess_msgtype_from_suffix(as_path(pathNfilename))
+                {
+                    (*msg).type_0 = type_;
+                    (*msg).param.set(Param::MimeType, mime);
                 }
-                free(better_mime as *mut libc::c_void);
             } else if !(*msg).param.exists(Param::MimeType) {
-                let mut better_mime = std::ptr::null_mut();
-
-                dc_msg_guess_msgtype_from_suffix(pathNfilename, ptr::null_mut(), &mut better_mime);
-
-                if !better_mime.is_null() {
-                    (*msg).param.set(Param::MimeType, as_str(better_mime));
+                if let Some((_, mime)) = dc_msg_guess_msgtype_from_suffix(as_path(pathNfilename)) {
+                    (*msg).param.set(Param::MimeType, mime);
                 }
-                free(better_mime as *mut _);
             }
             info!(
                 context,
diff --git a/src/dc_msg.rs b/src/dc_msg.rs
index d443cee84..bb6b578ef 100644
--- a/src/dc_msg.rs
+++ b/src/dc_msg.rs
@@ -270,36 +270,23 @@ pub unsafe fn dc_msg_empty(mut msg: *mut dc_msg_t) {
 }
 
 pub unsafe fn dc_msg_get_filemime(msg: *const dc_msg_t) -> *mut libc::c_char {
-    let mut ret = 0 as *mut libc::c_char;
+    if msg.is_null() {
+        return dc_strdup(0 as *const libc::c_char);
+    }
 
-    if !msg.is_null() {
-        match (*msg).param.get(Param::MimeType) {
-            Some(m) => {
-                ret = m.strdup();
-            }
-            None => {
-                if let Some(file) = (*msg).param.get(Param::File) {
-                    let file_c = CString::yolo(file);
-                    dc_msg_guess_msgtype_from_suffix(file_c.as_ptr(), 0 as *mut Viewtype, &mut ret);
-                    if ret.is_null() {
-                        ret = dc_strdup(
-                            b"application/octet-stream\x00" as *const u8 as *const libc::c_char,
-                        )
-                    }
-                }
-            }
+    if let Some(m) = (*msg).param.get(Param::MimeType) {
+        return m.strdup();
+    } else if let Some(file) = (*msg).param.get(Param::File) {
+        if let Some((_, mime)) = dc_msg_guess_msgtype_from_suffix(Path::new(file)) {
+            return mime.strdup();
         }
     }
 
-    if !ret.is_null() {
-        return ret;
-    }
-
-    dc_strdup(0 as *const libc::c_char)
+    "application/octet-stream".strdup()
 }
 
 #[allow(non_snake_case)]
-pub unsafe fn dc_msg_guess_msgtype_from_suffix(
+pub unsafe fn dc_msg_guess_msgtype_from_suffix0(
     pathNfilename: *const libc::c_char,
     mut ret_msgtype: *mut Viewtype,
     mut ret_mime: *mut *mut libc::c_char,
@@ -353,7 +340,7 @@ pub unsafe fn dc_msg_guess_msgtype_from_suffix(
     free(dummy_buf as *mut libc::c_void);
 }
 
-pub fn dc_msg_guess_msgtype_from_suffix2(path: &Path) -> Option<(Viewtype, &str)> {
+pub fn dc_msg_guess_msgtype_from_suffix(path: &Path) -> Option<(Viewtype, &str)> {
     let known = hashmap! {
         "mp3"   => (Viewtype::Audio, "audio/mpeg"),
         "aac"   => (Viewtype::Audio, "audio/aac"),