diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index c1446218367e4..cae2f405318be 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -43,9 +43,12 @@ cc = "1.0"
 build_helper = { path = "../build_helper" }
 
 [features]
+default = ["compiler_builtins_c"]
+
 backtrace = []
 panic-unwind = ["panic_unwind"]
 profiler = ["profiler_builtins"]
+compiler_builtins_c = ["compiler_builtins/c"]
 
 # Make panics and failed asserts immediately abort without formatting any message
 panic_immediate_abort = ["core/panic_immediate_abort"]
diff --git a/src/rustc/compiler_builtins_shim/Cargo.toml b/src/rustc/compiler_builtins_shim/Cargo.toml
index 7d8423ca84eb4..9804177280f66 100644
--- a/src/rustc/compiler_builtins_shim/Cargo.toml
+++ b/src/rustc/compiler_builtins_shim/Cargo.toml
@@ -34,7 +34,7 @@ cc = "1.0.1"
 
 [features]
 c = []
-default = ["c", "rustbuild", "compiler-builtins"]
+default = ["rustbuild", "compiler-builtins"]
 mem = []
 rustbuild = []
 compiler-builtins = []