diff --git a/Cargo.lock b/Cargo.lock
index 5f79e4b..c740bcd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -92,18 +92,18 @@ dependencies = [
 
 [[package]]
 name = "bit-set"
-version = "0.5.3"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0700ddab506f33b20a03b13996eccd309a48e5ff77d0d95926aa0210fb4e95f1"
+checksum = "08807e080ed7f9d5433fa9b275196cfc35414f66a0c79d864dc51a0d825231a3"
 dependencies = [
  "bit-vec",
 ]
 
 [[package]]
 name = "bit-vec"
-version = "0.6.3"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "349f9b6a179ed607305526ca489b34ad0a41aed5f7980fa90eb03160b69598fb"
+checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
 
 [[package]]
 name = "bitflags"
@@ -519,12 +519,6 @@ version = "0.2.168"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5aaeb2981e0606ca11d79718f8bb01164f1d6ed75080182d3abf017e6d244b6d"
 
-[[package]]
-name = "libm"
-version = "0.2.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "348108ab3fba42ec82ff6e9564fc4ca0247bdccdc68dd8af9764bbc79c3c8ffb"
-
 [[package]]
 name = "linux-raw-sys"
 version = "0.3.8"
@@ -598,7 +592,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
- "libm",
 ]
 
 [[package]]
@@ -713,9 +706,9 @@ dependencies = [
 
 [[package]]
 name = "proptest"
-version = "1.5.0"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4c2511913b88df1637da85cc8d96ec8e43a3f8bb8ccb71ee1ac240d6f3df58d"
+checksum = "14cae93065090804185d3b75f0bf93b8eeda30c7a9b4a33d3bdb3988d6229e50"
 dependencies = [
  "bit-set",
  "bit-vec",
diff --git a/Cargo.toml b/Cargo.toml
index a2b3ec6..8581607 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -53,4 +53,4 @@ slog-async = "2.8"
 slog-term = "2.9"
 structopt = "0.3"
 subprocess = "0.2.6"
-proptest = "1.5.0"
+proptest = "1.6.0"