diff --git a/Cargo.lock b/Cargo.lock
index 2ddbd8f3b..dff759c6c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -613,7 +613,7 @@ dependencies = [
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "md5 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha1 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha3 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -924,7 +924,7 @@ dependencies = [
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
 ]
 
@@ -1128,7 +1128,7 @@ dependencies = [
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
 ]
 
@@ -1229,7 +1229,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1248,7 +1248,7 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.5.0"
+version = "0.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2199,7 +2199,7 @@ dependencies = [
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
 "checksum regex 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a62bf8bb734ab90b7f234b681b01af396e5d39b028906c210dc04fa1d5e9e5b3"
 "checksum regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "75ecf88252dce580404a22444fc7d626c01815debba56a7f4f536772a5ff19d3"
-"checksum regex-syntax 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "48d7391e7e90e06eaf3aefbe4652464153ecfec64806f3bf77ffc59638a63e77"
+"checksum regex-syntax 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7d707a4fa2637f2dca2ef9fd02225ec7661fe01a53623c1e6515b6916511f7a7"
 "checksum regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8f1ac0f60d675cc6cf13a20ec076568254472551051ad5dd050364d70671bf6b"
 "checksum remove_dir_all 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0882bc41b0ba6131c7f0ce97233b62d8099e3f3abc60d4938185d3e35439c0cc"
 "checksum remove_dir_all 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b5d2f806b0fcdabd98acd380dc8daef485e22bcb7cddc811d1337967f2528cf5"
diff --git a/src/hashsum/Cargo.toml b/src/hashsum/Cargo.toml
index b328881da..9250f305f 100644
--- a/src/hashsum/Cargo.toml
+++ b/src/hashsum/Cargo.toml
@@ -15,7 +15,7 @@ hex = "0.2.0"
 libc = "0.2.42"
 md5 = "0.3.5"
 regex = "0.2.2"
-regex-syntax = "0.5.0"
+regex-syntax = "0.6.0"
 sha1 = "0.6.0"
 sha2 = "0.6.0"
 sha3 = "0.6.0"
diff --git a/src/nl/Cargo.toml b/src/nl/Cargo.toml
index ae1ad9aec..2dd448ae6 100644
--- a/src/nl/Cargo.toml
+++ b/src/nl/Cargo.toml
@@ -14,7 +14,7 @@ libc = "0.2.42"
 aho-corasick = "0.6.3"
 memchr = "1.0.1"
 regex = "0.2.2"
-regex-syntax = "0.5.0"
+regex-syntax = "0.6.0"
 uucore = { path="../uucore" }
 
 [[bin]]
diff --git a/src/ptx/Cargo.toml b/src/ptx/Cargo.toml
index f717d644b..5b1404a2c 100644
--- a/src/ptx/Cargo.toml
+++ b/src/ptx/Cargo.toml
@@ -13,7 +13,7 @@ getopts = "0.2.14"
 libc = "0.2.42"
 aho-corasick = "0.6.3"
 memchr = "1.0.1"
-regex-syntax = "0.5.0"
+regex-syntax = "0.6.0"
 regex = "0.2.2"
 uucore = { path="../uucore" }