diff --git a/src/constants.rs b/src/constants.rs
index 56b01ec18..b0aca01b7 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -1,5 +1,5 @@
 //! Constants
-#![allow(non_camel_case_types)]
+#![allow(non_camel_case_types, dead_code)]
 
 use lazy_static::lazy_static;
 
diff --git a/src/dc_array.rs b/src/dc_array.rs
index dffa9d2ef..a2f744259 100644
--- a/src/dc_array.rs
+++ b/src/dc_array.rs
@@ -259,10 +259,7 @@ pub fn dc_array_new(initsize: size_t) -> *mut dc_array_t {
     dc_array_t::new(initsize).into_raw()
 }
 
-fn dc_array_new_locations(initsize: size_t) -> *mut dc_array_t {
-    dc_array_t::new_locations(initsize).into_raw()
-}
-
+#[cfg(test)]
 unsafe fn dc_array_empty(array: *mut dc_array_t) {
     assert!(!array.is_null());
 
diff --git a/src/dc_mimeparser.rs b/src/dc_mimeparser.rs
index 978963133..b41f04d9a 100644
--- a/src/dc_mimeparser.rs
+++ b/src/dc_mimeparser.rs
@@ -61,11 +61,6 @@ pub struct dc_mimeparser_t<'a> {
     pub message_kml: Option<dc_kml_t>,
 }
 
-// deprecated
-unsafe fn dc_no_compound_msgs() {
-    S_GENERATE_COMPOUND_MSGS = 0i32;
-}
-
 // deprecated: flag to switch generation of compound messages on and off.
 static mut S_GENERATE_COMPOUND_MSGS: libc::c_int = 1i32;
 
diff --git a/src/dc_strencode.rs b/src/dc_strencode.rs
index 1afd9cb3c..4aff165d3 100644
--- a/src/dc_strencode.rs
+++ b/src/dc_strencode.rs
@@ -331,6 +331,7 @@ pub unsafe fn dc_decode_header_words(in_0: *const libc::c_char) -> *mut libc::c_
     out
 }
 
+#[cfg(test)]
 unsafe fn dc_encode_modified_utf7(
     mut to_encode: *const libc::c_char,
     change_spaces: libc::c_int,
@@ -475,12 +476,14 @@ unsafe fn dc_encode_modified_utf7(
  ******************************************************************************/
 
 // UTF7 modified base64 alphabet
+#[cfg(test)]
 static mut BASE64CHARS: [libc::c_char; 65] = [
     65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
     89, 90, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114,
     115, 116, 117, 118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 44, 0,
 ];
 
+#[cfg(test)]
 unsafe fn dc_decode_modified_utf7(
     to_decode: *const libc::c_char,
     change_spaces: libc::c_int,
diff --git a/src/dc_tools.rs b/src/dc_tools.rs
index f93e9da10..2ba17566c 100644
--- a/src/dc_tools.rs
+++ b/src/dc_tools.rs
@@ -193,6 +193,7 @@ pub unsafe fn dc_null_terminate(
     out
 }
 
+#[cfg(test)]
 unsafe fn dc_binary_to_uc_hex(buf: *const uint8_t, bytes: size_t) -> *mut libc::c_char {
     if buf.is_null() || bytes == 0 {
         return std::ptr::null_mut();
@@ -225,10 +226,6 @@ pub unsafe fn dc_remove_cr_chars(buf: *mut libc::c_char) {
     *p2 = 0 as libc::c_char;
 }
 
-unsafe fn dc_unify_lineends(buf: *mut libc::c_char) {
-    dc_remove_cr_chars(buf);
-}
-
 /* replace bad UTF-8 characters by sequences of `_` (to avoid problems in filenames, we do not use eg. `?`) the function is useful if strings are unexpectingly encoded eg. as ISO-8859-1 */
 #[allow(non_snake_case)]
 pub unsafe fn dc_replace_bad_utf8_chars(buf: *mut libc::c_char) {
@@ -295,6 +292,7 @@ pub unsafe fn dc_replace_bad_utf8_chars(buf: *mut libc::c_char) {
     }
 }
 
+#[cfg(test)]
 unsafe fn dc_utf8_strlen(s: *const libc::c_char) -> size_t {
     if s.is_null() {
         return 0;
@@ -413,6 +411,7 @@ pub unsafe fn dc_free_splitted_lines(lines: Vec<*mut libc::c_char>) {
 }
 
 /* insert a break every n characters, the return must be free()'d */
+#[cfg(test)]
 unsafe fn dc_insert_breaks(
     in_0: *const libc::c_char,
     break_every: libc::c_int,
diff --git a/src/lib.rs b/src/lib.rs
index 8ac561b2b..76cacfd37 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -65,7 +65,5 @@ mod dc_strencode;
 mod dc_token;
 pub mod dc_tools;
 
-use self::constants::*;
-
 #[cfg(test)]
 mod test_utils;
diff --git a/src/types.rs b/src/types.rs
index 93fbd973d..41f9bb50f 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -34,14 +34,9 @@ pub type dc_precheck_imf_t =
 pub type dc_set_config_t = fn(_: &Context, _: &str, _: Option<&str>) -> ();
 pub type dc_get_config_t = fn(_: &Context, _: &str) -> Option<String>;
 
-type sqlite_int64 = i64;
-type sqlite3_int64 = sqlite_int64;
-
 pub type int32_t = i32;
-type int64_t = i64;
 pub type uintptr_t = libc::uintptr_t;
 pub type size_t = libc::size_t;
-type ssize_t = libc::ssize_t;
 pub type uint32_t = libc::c_uint;
 pub type uint8_t = libc::c_uchar;
 pub type uint16_t = libc::c_ushort;