diff --git a/Cargo.lock b/Cargo.lock
index 2fe67f677..89cbd1875 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -298,10 +298,10 @@ dependencies = [
 
 [[package]]
 name = "cpp"
-version = "0.3.2"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cpp_macros 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cpp_macros 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -327,17 +327,28 @@ dependencies = [
  "quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "cpp_common"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cpp_syn 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cpp_synom 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "cpp_macros"
-version = "0.3.2"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "aho-corasick 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "cpp_common 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cpp_common 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpp_syn 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpp_synom 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -751,7 +762,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "libstdbuf"
 version = "0.0.1"
 dependencies = [
- "cpp 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cpp 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpp_build 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
@@ -2056,10 +2067,11 @@ dependencies = [
 "checksum clippy 0.0.211 (registry+https://github.com/rust-lang/crates.io-index)" = "88130e594af68f9cfd8835fe9a1329b575f57e39e79ac65818f24b3dc27995d9"
 "checksum clippy_lints 0.0.211 (registry+https://github.com/rust-lang/crates.io-index)" = "af5c9410d051eeb63e8f9535271477677df56b05b4ed6be8c7c14a9646a413db"
 "checksum cmake 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)" = "56d741ea7a69e577f6d06b36b7dff4738f680593dc27a701ffa8506b73ce28bb"
-"checksum cpp 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b244cf36c028e27227d6e7f9963c768dff5a1c06d5e01ff97f12ef4e05afd57c"
+"checksum cpp 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2d1cd8699ffa1b18fd388183f7762e0545eddbd5c6ec95e9e3b42a4a71a507ff"
 "checksum cpp_build 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e9aebc7c97550a8c6a1f48dbaf078b033dc546e1b5badde300767099d4cace8f"
 "checksum cpp_common 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4ca58053cb5433ac7d3852eeee6a58314762bdbcbcd765a8f9a4f0e66bf90c72"
-"checksum cpp_macros 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "569d52f48c31a5d9ecc749340d355a2d4b80de91d950164bcca7a7580bd2189b"
+"checksum cpp_common 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "79e39149a7943affa02f5b6e347ca2840a129cc78d5883ee229f0f1c4027d628"
+"checksum cpp_macros 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6bba562eb4d65561efb6cef4e5f0de5936edfee7c6af7a4dfc323f6f2c997e40"
 "checksum cpp_syn 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a8cd649bf5b3804d92fe12a60c7698f5a538a6033ed8a668bf5241d4d4f1644e"
 "checksum cpp_synmap 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "897e4f9cdbe2874edd3ffe53718ee5d8b89e2a970057b2c93d3214104f2e90b6"
 "checksum cpp_synom 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1fc8da5694233b646150c785118f77835ad0a49680c7f312a10ef30957c67b6d"
diff --git a/src/stdbuf/libstdbuf/Cargo.toml b/src/stdbuf/libstdbuf/Cargo.toml
index 0018e9541..31f59ba92 100644
--- a/src/stdbuf/libstdbuf/Cargo.toml
+++ b/src/stdbuf/libstdbuf/Cargo.toml
@@ -12,7 +12,7 @@ crate-type = ["cdylib", "rlib"]
 [dependencies]
 uucore = { path="../../uucore" }
 libc = "0.2"
-cpp = "0.3"
+cpp = "0.4"
 
 [build-dependencies]
 cpp_build = "0.3"