diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 5fc58c8ab5a7b..bfe7d12d9d0ba 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -112,6 +112,7 @@
 #![feature(maybe_uninit_extra, maybe_uninit_slice, maybe_uninit_array)]
 #![feature(alloc_layout_extra)]
 #![feature(try_trait)]
+#![feature(mem_take)]
 
 // Allow testing this library
 
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 04c50329de3d0..d2d08a075b92c 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -126,6 +126,7 @@
 #![feature(adx_target_feature)]
 #![feature(maybe_uninit_slice, maybe_uninit_array)]
 #![feature(external_doc)]
+#![feature(mem_take)]
 
 #[prelude_import]
 #[allow(unused)]
diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index 1e0f1ed578aae..2c097238b95b2 100644
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -25,6 +25,7 @@
 #![feature(extern_types)]
 #![feature(in_band_lifetimes)]
 #![feature(optin_builtin_traits)]
+#![feature(mem_take)]
 #![feature(non_exhaustive)]
 #![feature(specialization)]
 
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 257d5159f1131..390ad09a40406 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -65,6 +65,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(proc_macro_hygiene)]
 #![feature(log_syntax)]
+#![feature(mem_take)]
 
 #![recursion_limit="512"]
 
diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs
index 7283aa95b3027..f6d8b41f71062 100644
--- a/src/librustc_codegen_llvm/lib.rs
+++ b/src/librustc_codegen_llvm/lib.rs
@@ -21,6 +21,7 @@
 #![feature(link_args)]
 #![feature(static_nobundle)]
 #![feature(trusted_len)]
+#![feature(mem_take)]
 #![deny(rust_2018_idioms)]
 #![deny(internal)]
 #![deny(unused_lifetimes)]
diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs
index b76f098773f0b..3c1ab600040a1 100644
--- a/src/librustc_codegen_ssa/lib.rs
+++ b/src/librustc_codegen_ssa/lib.rs
@@ -10,6 +10,7 @@
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
 #![feature(trusted_len)]
+#![feature(mem_take)]
 #![allow(unused_attributes)]
 #![allow(dead_code)]
 #![deny(rust_2018_idioms)]
diff --git a/src/librustc_mir/lib.rs b/src/librustc_mir/lib.rs
index cb02e1a778c93..b85149cf55676 100644
--- a/src/librustc_mir/lib.rs
+++ b/src/librustc_mir/lib.rs
@@ -24,6 +24,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(slice_concat_ext)]
 #![feature(trusted_len)]
 #![feature(try_blocks)]
+#![feature(mem_take)]
 
 #![recursion_limit="256"]
 
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index f4c23a023b104..3bc4da78e18af 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -4,6 +4,7 @@
 
 #![feature(crate_visibility_modifier)]
 #![feature(label_break_value)]
+#![feature(mem_take)]
 #![feature(nll)]
 #![feature(rustc_diagnostic_macros)]
 #![cfg_attr(bootstrap, feature(type_alias_enum_variants))]
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 85ae55b2dd946..2b9ee0a746dce 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -69,6 +69,7 @@ This API is completely unstable and subject to change.
 #![feature(slice_patterns)]
 #![feature(never_type)]
 #![feature(inner_deref)]
+#![feature(mem_take)]
 
 #![recursion_limit="256"]
 
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index ba423300e0277..342264db43c79 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -21,6 +21,7 @@
 #![feature(drain_filter)]
 #![feature(inner_deref)]
 #![feature(never_type)]
+#![feature(mem_take)]
 
 #![recursion_limit="256"]
 
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 60e06139eba99..fb9a228880eb7 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -272,6 +272,7 @@
 #![feature(libc)]
 #![feature(link_args)]
 #![feature(linkage)]
+#![feature(mem_take)]
 #![feature(needs_panic_runtime)]
 #![feature(never_type)]
 #![feature(nll)]
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 337b84247361d..72b5f8c9f3f8b 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -16,6 +16,7 @@
 #![feature(const_transmute)]
 #![feature(crate_visibility_modifier)]
 #![feature(label_break_value)]
+#![feature(mem_take)]
 #![feature(nll)]
 #![feature(rustc_attrs)]
 #![feature(rustc_diagnostic_macros)]
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 597fdf2d95e30..517f2a362f554 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -1,4 +1,5 @@
 #![crate_name = "compiletest"]
+#![feature(mem_take)]
 #![feature(test)]
 #![feature(vec_remove_item)]
 #![deny(warnings, rust_2018_idioms)]