diff --git a/src/x.rs b/src/x.rs
index 9d74ddc11..282395516 100644
--- a/src/x.rs
+++ b/src/x.rs
@@ -76,3 +76,16 @@ pub use libc::atof;
 pub unsafe fn atof(nptr: *mut libc::c_char) -> libc::c_double {
     libc::strtod(nptr, std::ptr::null_mut())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_atox() {
+        unsafe {
+            assert_eq!(atol(b"\x00" as *const u8 as *const libc::c_char), 0);
+            assert_eq!(atoi(b"\x00" as *const u8 as *const libc::c_char), 0);
+        }
+    }
+}
diff --git a/tests/stress.rs b/tests/stress.rs
index 3e3112304..655710075 100644
--- a/tests/stress.rs
+++ b/tests/stress.rs
@@ -544,30 +544,6 @@ unsafe fn stress_functions(context: &dc_context_t) {
     } else {
     };
     free(mime_0 as *mut libc::c_void);
-    if 0 != !(atol(b"\x00" as *const u8 as *const libc::c_char) == 0i32 as libc::c_long)
-        as libc::c_int as libc::c_long
-    {
-        __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,
-            370i32,
-            b"atol(\"\")==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    if 0 != !(atoi(b"\x00" as *const u8 as *const libc::c_char) == 0i32) as libc::c_int
-        as libc::c_long
-    {
-        __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,
-            371i32,
-            b"atoi(\"\")==0\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
     let f: libc::c_double = dc_atof(b"1.23\x00" as *const u8 as *const libc::c_char);
     if 0 != !(f > 1.22f64 && f < 1.24f64) as libc::c_int as libc::c_long {
         __assert_rtn(