diff --git a/.travis.yml b/.travis.yml
index 3508be4a9..f2774e73a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -70,7 +70,7 @@ matrix:
     script: ./ci/crossbeam-utils.sh
 
   # Check for duplicate dependencies.
-  - rust: stable
+  - rust: nightly
     name: "dependency tree check"
     script: ./ci/dependencies.sh
 
diff --git a/Cargo.toml b/Cargo.toml
index 205301e2d..45a848eb1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,7 +25,7 @@ nightly = ["crossbeam-epoch/nightly", "crossbeam-utils/nightly"]
 std = ["crossbeam-epoch/std", "crossbeam-utils/std"]
 
 [dependencies]
-cfg-if = "0.1"
+cfg-if = "0.1.2"
 
 [dependencies.crossbeam-channel]
 version = "0.3.7"
diff --git a/ci/dependencies.sh b/ci/dependencies.sh
index 5153d93de..cebbbde46 100755
--- a/ci/dependencies.sh
+++ b/ci/dependencies.sh
@@ -11,4 +11,9 @@ cargo tree
 cargo tree --duplicate
 cargo tree --duplicate || exit 1
 
+# Check minimal versions.
+cargo update -Zminimal-versions
+cargo tree
+cargo check --all --all-features --exclude benchmarks
+
 exit 0
diff --git a/crossbeam-channel/Cargo.toml b/crossbeam-channel/Cargo.toml
index ac5a19f5d..1d9a0bc88 100644
--- a/crossbeam-channel/Cargo.toml
+++ b/crossbeam-channel/Cargo.toml
@@ -16,7 +16,7 @@ keywords = ["channel", "mpmc", "select", "golang", "message"]
 categories = ["algorithms", "concurrency", "data-structures"]
 
 [dependencies]
-smallvec = "0.6.2"
+smallvec = "0.6.9"
 
 [dependencies.crossbeam-utils]
 version = "0.6.5"
diff --git a/crossbeam-channel/benchmarks/Cargo.toml b/crossbeam-channel/benchmarks/Cargo.toml
index 0304b50db..9b3c1c0a3 100644
--- a/crossbeam-channel/benchmarks/Cargo.toml
+++ b/crossbeam-channel/benchmarks/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
 name = "benchmarks"
 version = "0.1.0"
+publish = false
 
 [dependencies]
 atomicring = "1.1.1"
diff --git a/crossbeam-epoch/Cargo.toml b/crossbeam-epoch/Cargo.toml
index bb04d6852..50d41f107 100644
--- a/crossbeam-epoch/Cargo.toml
+++ b/crossbeam-epoch/Cargo.toml
@@ -22,7 +22,7 @@ std = ["crossbeam-utils/std", "lazy_static"]
 sanitize = [] # Makes it more likely to trigger any potential data races.
 
 [dependencies]
-cfg-if = "0.1"
+cfg-if = "0.1.2"
 memoffset = "0.2"
 
 [dependencies.arrayvec]
diff --git a/crossbeam-skiplist/Cargo.toml b/crossbeam-skiplist/Cargo.toml
index b85175e12..6c71aabd7 100644
--- a/crossbeam-skiplist/Cargo.toml
+++ b/crossbeam-skiplist/Cargo.toml
@@ -21,7 +21,7 @@ nightly = ["crossbeam-epoch/nightly", "crossbeam-utils/nightly"]
 std = ["crossbeam-epoch/std", "crossbeam-utils/std"]
 
 [dependencies]
-cfg-if = "0.1"
+cfg-if = "0.1.2"
 
 [dependencies.crossbeam-epoch]
 version = "0.7"
diff --git a/crossbeam-utils/Cargo.toml b/crossbeam-utils/Cargo.toml
index 10d424dc4..67554c025 100644
--- a/crossbeam-utils/Cargo.toml
+++ b/crossbeam-utils/Cargo.toml
@@ -21,7 +21,7 @@ nightly = []
 std = ["lazy_static"]
 
 [dependencies]
-cfg-if = "0.1"
+cfg-if = "0.1.2"
 lazy_static = { version = "1.1.0", optional = true }
 
 [dev-dependencies]