diff --git a/testing/geckodriver/Cargo.lock b/testing/geckodriver/Cargo.lock
index c3e55df36726..9e310282d71b 100644
--- a/testing/geckodriver/Cargo.lock
+++ b/testing/geckodriver/Cargo.lock
@@ -8,7 +8,7 @@ dependencies = [
  "lazy_static 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mozprofile 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozrunner 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mozrunner 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "mozversion 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -296,7 +296,7 @@ dependencies = [
 
 [[package]]
 name = "mozrunner"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -724,7 +724,7 @@ dependencies = [
 "checksum mime 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "9d69889cdc6336ed56b174514ce876c4c3dc564cc23dd872e7bca589bb2a36c8"
 "checksum miniz-sys 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "28eaee17666671fa872e567547e8428e83308ebe5808cdf6a0e28397dbe2c726"
 "checksum mozprofile 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1a17b8bbde1dc0fbf1c8b073192d7c6f89baa932173ece7c1447de5e9cc7cd7e"
-"checksum mozrunner 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "68e6a21ef32a737399a34d9a89640b350d8b47ef03457225c0c223842cf2311f"
+"checksum mozrunner 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9d113eaa876c004ad5119224e318b36fd358658e47cdd49b45d209b2d7ac82"
 "checksum mozversion 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9fb3a40135553611560d3eb4a49479beaf0c91c5a93f723338c5b0edddf08f26"
 "checksum msdos_time 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "65ba9d75bcea84e07812618fedf284a64776c2f2ea0cad6bca7f69739695a958"
 "checksum num 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)" = "98b15ba84e910ea7a1973bccd3df7b31ae282bf9d8bd2897779950c9b8303d40"
diff --git a/testing/geckodriver/Cargo.toml b/testing/geckodriver/Cargo.toml
index e4b6925dab42..f07ed58bfb65 100644
--- a/testing/geckodriver/Cargo.toml
+++ b/testing/geckodriver/Cargo.toml
@@ -18,7 +18,7 @@ hyper = "0.10"
 lazy_static = "0.1"
 log = "0.3"
 mozprofile = "0.3.0"
-mozrunner = "0.4.1"
+mozrunner = "0.4.2"
 mozversion = "0.1.2"
 regex = "0.2"
 rustc-serialize = "0.3"