diff --git a/src/dc_strencode.rs b/src/dc_strencode.rs
index b6d6d4e22..66f3ffb9f 100644
--- a/src/dc_strencode.rs
+++ b/src/dc_strencode.rs
@@ -898,4 +898,62 @@ mod tests {
         unsafe { print_hex(hex.as_mut_ptr(), cur) };
         assert_eq!(to_string(hex.as_ptr() as *const _), "=3A");
     }
+
+    #[test]
+    fn test_dc_urlencode_urldecode() {
+        unsafe {
+            let buf1 =
+                dc_urlencode(b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char);
+
+            assert_eq!(
+                CStr::from_ptr(buf1 as *const libc::c_char)
+                    .to_str()
+                    .unwrap(),
+                "Bj%C3%B6rn+Petersen"
+            );
+
+            let buf2 = dc_urldecode(buf1);
+
+            assert_eq!(
+                strcmp(
+                    buf2,
+                    b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char
+                ),
+                0
+            );
+
+            free(buf1 as *mut libc::c_void);
+            free(buf2 as *mut libc::c_void);
+        }
+    }
+
+    #[test]
+    fn test_dc_encode_decode_modified_utf7() {
+        unsafe {
+            let buf1 = dc_encode_modified_utf7(
+                b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char,
+                1,
+            );
+
+            assert_eq!(
+                CStr::from_ptr(buf1 as *const libc::c_char)
+                    .to_str()
+                    .unwrap(),
+                "Bj&APY-rn_Petersen"
+            );
+
+            let buf2 = dc_decode_modified_utf7(buf1, 1);
+
+            assert_eq!(
+                strcmp(
+                    buf2,
+                    b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char
+                ),
+                0
+            );
+
+            free(buf1 as *mut libc::c_void);
+            free(buf2 as *mut libc::c_void);
+        }
+    }
 }
diff --git a/src/dc_tools.rs b/src/dc_tools.rs
index 9379607f7..642d10cb3 100644
--- a/src/dc_tools.rs
+++ b/src/dc_tools.rs
@@ -1816,4 +1816,70 @@ mod tests {
 
         unsafe { free(raw as *mut _) };
     }
+
+    #[test]
+    fn test_dc_replace_bad_utf8_chars_1() {
+        unsafe {
+            let buf1 = strdup(b"ol\xc3\xa1 mundo <>\"\'& \xc3\xa4\xc3\x84\xc3\xb6\xc3\x96\xc3\xbc\xc3\x9c\xc3\x9f foo\xc3\x86\xc3\xa7\xc3\x87 \xe2\x99\xa6&noent;\x00" as *const u8 as *const libc::c_char);
+            let buf2 = strdup(buf1);
+
+            dc_replace_bad_utf8_chars(buf2);
+
+            assert_eq!(strcmp(buf1, buf2), 0);
+
+            free(buf1 as *mut libc::c_void);
+            free(buf2 as *mut libc::c_void);
+        }
+    }
+
+    #[test]
+    fn test_dc_replace_bad_utf8_chars_2() {
+        unsafe {
+            let buf1 = strdup(b"ISO-String with Ae: \xc4\x00" as *const u8 as *const libc::c_char);
+            let buf2 = strdup(buf1);
+
+            dc_replace_bad_utf8_chars(buf2);
+
+            assert_eq!(
+                CStr::from_ptr(buf2 as *const libc::c_char)
+                    .to_str()
+                    .unwrap(),
+                "ISO-String with Ae: _"
+            );
+
+            free(buf1 as *mut libc::c_void);
+            free(buf2 as *mut libc::c_void);
+        }
+    }
+
+    #[test]
+    fn test_dc_replace_bad_utf8_chars_3() {
+        unsafe {
+            let buf1 = strdup(b"\x00" as *const u8 as *const libc::c_char);
+            let buf2 = strdup(buf1);
+
+            dc_replace_bad_utf8_chars(buf2);
+
+            assert_eq!(*buf2.offset(0), 0);
+
+            free(buf1 as *mut libc::c_void);
+            free(buf2 as *mut libc::c_void);
+        }
+    }
+
+    #[test]
+    fn test_dc_replace_bad_utf8_chars_4() {
+        unsafe {
+            dc_replace_bad_utf8_chars(0 as *mut libc::c_char);
+        }
+    }
+
+    #[test]
+    fn test_dc_create_id() {
+        unsafe {
+            let buf = dc_create_id();
+            assert_eq!(strlen(buf), 11);
+            free(buf as *mut libc::c_void);
+        }
+    }
 }
diff --git a/tests/stress.rs b/tests/stress.rs
index 213ea2156..95c4813e6 100644
--- a/tests/stress.rs
+++ b/tests/stress.rs
@@ -413,138 +413,6 @@ unsafe fn stress_functions(context: &Context) {
         free(fn0 as *mut libc::c_void);
         free(fn1 as *mut libc::c_void);
     }
-
-    let mut buf1: *mut libc::c_char =
-        strdup(b"ol\xc3\xa1 mundo <>\"\'& \xc3\xa4\xc3\x84\xc3\xb6\xc3\x96\xc3\xbc\xc3\x9c\xc3\x9f foo\xc3\x86\xc3\xa7\xc3\x87 \xe2\x99\xa6&noent;\x00"
-                   as *const u8 as *const libc::c_char);
-    let mut buf2: *mut libc::c_char = strdup(buf1);
-    dc_replace_bad_utf8_chars(buf2);
-    if 0 != !(strcmp(buf1, buf2) == 0i32) as usize {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            512i32,
-            b"strcmp(buf1, buf2)==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    free(buf2 as *mut libc::c_void);
-    buf1 = strdup(b"ISO-String with Ae: \xc4\x00" as *const u8 as *const libc::c_char);
-    buf2 = strdup(buf1);
-    dc_replace_bad_utf8_chars(buf2);
-    if 0 != !(strcmp(
-        b"ISO-String with Ae: _\x00" as *const u8 as *const libc::c_char,
-        buf2,
-    ) == 0i32) as usize
-    {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            517i32,
-            b"strcmp(\"ISO-String with Ae: _\", buf2)==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    free(buf2 as *mut libc::c_void);
-    buf1 = strdup(b"\x00" as *const u8 as *const libc::c_char);
-    buf2 = strdup(buf1);
-    dc_replace_bad_utf8_chars(buf2);
-    if 0 != !(*buf2.offset(0isize) as libc::c_int == 0i32) as usize {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            522i32,
-            b"buf2[0]==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    free(buf2 as *mut libc::c_void);
-    dc_replace_bad_utf8_chars(0 as *mut libc::c_char);
-    buf1 = dc_urlencode(b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char);
-    if 0 != !(strcmp(
-        buf1,
-        b"Bj%C3%B6rn+Petersen\x00" as *const u8 as *const libc::c_char,
-    ) == 0i32) as usize
-    {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            528i32,
-            b"strcmp(buf1, \"Bj%C3%B6rn+Petersen\") == 0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    buf2 = dc_urldecode(buf1);
-    if 0 != !(strcmp(
-        buf2,
-        b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char,
-    ) == 0i32) as usize
-    {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            530i32,
-            b"strcmp(buf2, \"Bj\xc3\xb6rn Petersen\") == 0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    free(buf2 as *mut libc::c_void);
-    buf1 = dc_create_id();
-    if 0 != !(strlen(buf1) == 11) as usize {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            534i32,
-            b"strlen(buf1) == DC_CREATE_ID_LEN\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    buf1 = dc_encode_modified_utf7(
-        b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char,
-        1i32,
-    );
-    if 0 != !(strcmp(
-        buf1,
-        b"Bj&APY-rn_Petersen\x00" as *const u8 as *const libc::c_char,
-    ) == 0i32) as usize
-    {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            600i32,
-            b"strcmp(buf1, \"Bj&APY-rn_Petersen\")==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    buf2 = dc_decode_modified_utf7(buf1, 1i32);
-    if 0 != !(strcmp(
-        buf2,
-        b"Bj\xc3\xb6rn Petersen\x00" as *const u8 as *const libc::c_char,
-    ) == 0i32) as usize
-    {
-        __assert_rtn(
-            (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))
-                .as_ptr(),
-            b"../cmdline/stress.c\x00" as *const u8 as *const libc::c_char,
-            602i32,
-            b"strcmp(buf2, \"Bj\xc3\xb6rn Petersen\")==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(buf1 as *mut libc::c_void);
-    free(buf2 as *mut libc::c_void);
     if 0 != !(2100i32 == 2100i32 || 2100i32 == 2052i32 || 2100i32 == 2055i32) as usize {
         __assert_rtn(
             (*::std::mem::transmute::<&[u8; 17], &[libc::c_char; 17]>(b"stress_functions\x00"))