diff --git a/src/dc_tools.rs b/src/dc_tools.rs
index 9075578d9..272d4f543 100644
--- a/src/dc_tools.rs
+++ b/src/dc_tools.rs
@@ -1704,4 +1704,23 @@ mod tests {
             );
         }
     }
+
+    #[test]
+    fn test_dc_atof() {
+        unsafe {
+            let f: libc::c_double = dc_atof(b"1.23\x00" as *const u8 as *const libc::c_char);
+            assert!(f > 1.22f64);
+            assert!(f < 1.24f64);
+        }
+    }
+
+    #[test]
+    fn test_dc_ftoa() {
+        unsafe {
+            let s: *mut libc::c_char = dc_ftoa(1.23f64);
+            assert!(dc_atof(s) > 1.22f64);
+            assert!(dc_atof(s) < 1.24f64);
+            free(s as *mut libc::c_void);
+        }
+    }
 }
diff --git a/tests/stress.rs b/tests/stress.rs
index 655710075..bb406f6b0 100644
--- a/tests/stress.rs
+++ b/tests/stress.rs
@@ -544,29 +544,6 @@ unsafe fn stress_functions(context: &dc_context_t) {
     } else {
     };
     free(mime_0 as *mut libc::c_void);
-    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(
-            (*::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,
-            374i32,
-            b"f>1.22 && f<1.24\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    let s: *mut libc::c_char = dc_ftoa(1.23f64);
-    if 0 != !(dc_atof(s) > 1.22f64 && dc_atof(s) < 1.24f64) 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,
-            377i32,
-            b"dc_atof(s)>1.22 && dc_atof(s)<1.24\x00" as *const u8 as *const libc::c_char,
-        );
-    } else {
-    };
-    free(s as *mut libc::c_void);
 
     let mut str: *mut libc::c_char = strdup(b"aaa\x00" as *const u8 as *const libc::c_char);
     let replacements: libc::c_int = dc_str_replace(