diff --git a/src/libcore/tests/num/bignum.rs b/src/libcore/tests/num/bignum.rs
index b9e15ec5c0763..50a3ec046ad13 100644
--- a/src/libcore/tests/num/bignum.rs
+++ b/src/libcore/tests/num/bignum.rs
@@ -1,4 +1,3 @@
-use std::prelude::v1::*;
 use core::num::bignum::tests::Big8x3 as Big;
 
 #[test]
diff --git a/src/libcore/tests/num/flt2dec/mod.rs b/src/libcore/tests/num/flt2dec/mod.rs
index a35897e9bc1ac..f85369ce40b8d 100644
--- a/src/libcore/tests/num/flt2dec/mod.rs
+++ b/src/libcore/tests/num/flt2dec/mod.rs
@@ -1,4 +1,3 @@
-use std::prelude::v1::*;
 use std::{str, i16, f32, f64, fmt};
 
 use core::num::flt2dec::{decode, DecodableFloat, FullDecoded, Decoded};
diff --git a/src/libcore/tests/num/flt2dec/strategy/dragon.rs b/src/libcore/tests/num/flt2dec/strategy/dragon.rs
index dc4d78bfae109..0c545b4d88714 100644
--- a/src/libcore/tests/num/flt2dec/strategy/dragon.rs
+++ b/src/libcore/tests/num/flt2dec/strategy/dragon.rs
@@ -1,4 +1,3 @@
-use std::prelude::v1::*;
 use super::super::*;
 use core::num::bignum::Big32x40 as Big;
 use core::num::flt2dec::strategy::dragon::*;