diff --git a/.github/workflows/test-release.yml b/.github/workflows/test-release.yml
index 7913bfda..6124b89f 100644
--- a/.github/workflows/test-release.yml
+++ b/.github/workflows/test-release.yml
@@ -12,7 +12,7 @@ jobs:
   test:
     strategy:
       matrix:
-        os: [ubuntu-16.04, ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-18.04, ubuntu-latest, macos-latest, windows-latest]
         rust_version: [stable]
         include:
         # check all tzs on most-recent OS's
@@ -30,7 +30,7 @@ jobs:
           rust_version: beta
         - os: ubuntu-latest
           rust_version: nightly
-        - os: ubuntu-16.04
+        - os: ubuntu-18.04
           rust_version: 1.13.0
         - os: macos-latest
           rust_version: 1.13.0
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 79d71296..fe10e03b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,7 +14,7 @@ jobs:
   test:
     strategy:
       matrix:
-        os: [ubuntu-16.04, ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-18.04, ubuntu-latest, macos-latest, windows-latest]
         rust_version: [stable]
         exhaustive_tz: [onetz]
         check_combinatoric: [no_combinatoric]
@@ -38,7 +38,7 @@ jobs:
           rust_version: beta
         - os: ubuntu-latest
           rust_version: nightly
-        - os: ubuntu-16.04
+        - os: ubuntu-18.04
           rust_version: 1.13.0
         - os: macos-latest
           rust_version: 1.13.0
diff --git a/src/format/mod.rs b/src/format/mod.rs
index 1cc5048c..ba1721d4 100644
--- a/src/format/mod.rs
+++ b/src/format/mod.rs
@@ -744,6 +744,9 @@ pub struct DelayedFormat<I> {
     /// An iterator returning formatting items.
     items: I,
     /// Locale used for text.
+    // TODO: Only used with the locale feature. We should make this property
+    // only present when the feature is enabled.
+    #[allow(dead_code)]
     locale: Option<Locale>,
 }
 
diff --git a/src/naive/datetime.rs b/src/naive/datetime.rs
index db23f540..a4b6002e 100644
--- a/src/naive/datetime.rs
+++ b/src/naive/datetime.rs
@@ -2307,7 +2307,7 @@ mod tests {
                 result.map(|(y, m, d, h, n, s)| NaiveDate::from_ymd(y, m, d).and_hms(h, n, s));
             assert_eq!(lhs.checked_add_signed(rhs), sum);
             assert_eq!(lhs.checked_sub_signed(-rhs), sum);
-        };
+        }
 
         check(
             (2014, 5, 6, 7, 8, 9),
diff --git a/src/naive/internals.rs b/src/naive/internals.rs
index 346063c3..4d7c1b3b 100644
--- a/src/naive/internals.rs
+++ b/src/naive/internals.rs
@@ -338,6 +338,7 @@ impl Of {
         (weekord / 7, Weekday::from_u32(weekord % 7).unwrap())
     }
 
+    #[cfg_attr(feature = "cargo-clippy", allow(wrong_self_convention))]
     #[inline]
     pub fn to_mdf(&self) -> Mdf {
         Mdf::from_of(*self)
@@ -460,6 +461,7 @@ impl Mdf {
         Mdf((mdf & !0b1111) | u32::from(flags))
     }
 
+    #[cfg_attr(feature = "cargo-clippy", allow(wrong_self_convention))]
     #[inline]
     pub fn to_of(&self) -> Of {
         Of::from_mdf(*self)