diff --git a/backend/telemetry_core/src/state/counter.rs b/backend/telemetry_core/src/state/counter.rs
index d3e12679..49ea4575 100644
--- a/backend/telemetry_core/src/state/counter.rs
+++ b/backend/telemetry_core/src/state/counter.rs
@@ -17,15 +17,15 @@
 use crate::feed_message::Ranking;
 use std::collections::HashMap;
 
-/// A data structure which counts how many occurences of a given key we've seen.
+/// A data structure which counts how many occurrences of a given key we've seen.
 #[derive(Default)]
 pub struct Counter<K> {
-    /// A map containing the number of occurences of a given key.
+    /// A map containing the number of occurrences of a given key.
     ///
     /// If there are none then the entry is removed.
     map: HashMap<K, u64>,
 
-    /// The number of occurences where the key is `None`.
+    /// The number of occurrences where the key is `None`.
     empty: u64,
 }
 
@@ -39,7 +39,7 @@ impl<K> Counter<K>
 where
     K: Sized + std::hash::Hash + Eq,
 {
-    /// Either adds or removes a single occurence of a given `key`.
+    /// Either adds or removes a single occurrence of a given `key`.
     pub fn modify<'a, Q>(&mut self, key: Option<&'a Q>, op: CounterValue)
     where
         Q: ?Sized + std::hash::Hash + Eq,
diff --git a/backend/telemetry_shard/src/json_message/hash.rs b/backend/telemetry_shard/src/json_message/hash.rs
index dd647c9d..efd5a7fa 100644
--- a/backend/telemetry_shard/src/json_message/hash.rs
+++ b/backend/telemetry_shard/src/json_message/hash.rs
@@ -50,7 +50,7 @@ impl<'de> Visitor<'de> for HashVisitor {
 
     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter.write_str(
-            "byte array of length 32, or hexidecimal string of 32 bytes beginning with 0x",
+            "byte array of length 32, or hexadecimal string of 32 bytes beginning with 0x",
         )
     }
 
diff --git a/backend/test_utils/src/lib.rs b/backend/test_utils/src/lib.rs
index bf0de0fa..b7d3cef9 100644
--- a/backend/test_utils/src/lib.rs
+++ b/backend/test_utils/src/lib.rs
@@ -21,7 +21,7 @@ pub mod server;
 /// is the slightly-lossy inverse of the custom serialization we do to feed messages.
 pub mod feed_message_de;
 
-/// A couple of macros to make it easier to test for the presense of things (mainly, feed messages)
+/// A couple of macros to make it easier to test for the presence of things (mainly, feed messages)
 /// in an iterable container.
 #[macro_use]
 pub mod contains_matches;