diff --git a/build.rs b/build.rs
index 37c9857..4dcf8e8 100644
--- a/build.rs
+++ b/build.rs
@@ -1,5 +1,6 @@
 extern crate autocfg;
 
+use autocfg::AutoCfg;
 use std::env;
 
 fn main() {
@@ -9,5 +10,9 @@ fn main() {
         autocfg::emit("has_i128");
     }
 
+    // The RangeBounds trait was stabilized in 1.28, so from that version onwards we
+    // implement that trait.
+    AutoCfg::new().unwrap().emit_rustc_version(1, 28);
+
     autocfg::rerun_path("build.rs");
 }
diff --git a/src/lib.rs b/src/lib.rs
index 97b232e..58ce531 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -84,6 +84,7 @@ fn unsigned<T: ToPrimitive>(x: &T) -> Option<u64> {
     }
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for Range<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.state)
@@ -173,6 +174,7 @@ where
     }
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for RangeInclusive<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.range.state)
@@ -248,6 +250,7 @@ pub struct RangeStep<A> {
     rev: bool,
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for RangeStep<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.state)
@@ -320,6 +323,7 @@ where
     }
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for RangeStepInclusive<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.state)
@@ -377,6 +381,7 @@ where
     }
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for RangeFrom<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.state)
@@ -430,6 +435,7 @@ where
     }
 }
 
+#[cfg(rustc_1_28)]
 impl<A> RangeBounds<A> for RangeStepFrom<A> {
     fn start_bound(&self) -> Bound<&A> {
         Bound::Included(&self.state)