diff --git a/cli/src/invocation/cmd/add.rs b/cli/src/invocation/cmd/add.rs
index e3054992d..0b3618f4e 100644
--- a/cli/src/invocation/cmd/add.rs
+++ b/cli/src/invocation/cmd/add.rs
@@ -13,7 +13,7 @@ pub(crate) fn execute<W: WriteColor>(
         _ => "(no description)".to_owned(),
     };
     let t = replica.new_task(Status::Pending, description).unwrap();
-    write!(w, "added task {}\n", t.get_uuid())?;
+    writeln!(w, "added task {}", t.get_uuid())?;
     Ok(())
 }
 
diff --git a/cli/src/invocation/cmd/gc.rs b/cli/src/invocation/cmd/gc.rs
index 1aa9e2161..5fe20b74e 100644
--- a/cli/src/invocation/cmd/gc.rs
+++ b/cli/src/invocation/cmd/gc.rs
@@ -4,7 +4,7 @@ use termcolor::WriteColor;
 
 pub(crate) fn execute<W: WriteColor>(w: &mut W, replica: &mut Replica) -> Fallible<()> {
     replica.gc()?;
-    write!(w, "garbage collected.\n")?;
+    writeln!(w, "garbage collected.")?;
     Ok(())
 }
 
diff --git a/cli/src/invocation/cmd/sync.rs b/cli/src/invocation/cmd/sync.rs
index 6115b4822..9abc8b657 100644
--- a/cli/src/invocation/cmd/sync.rs
+++ b/cli/src/invocation/cmd/sync.rs
@@ -8,7 +8,7 @@ pub(crate) fn execute<W: WriteColor>(
     server: &mut Box<dyn Server>,
 ) -> Fallible<()> {
     replica.sync(server)?;
-    write!(w, "sync complete.\n")?;
+    writeln!(w, "sync complete.")?;
     Ok(())
 }
 
diff --git a/cli/src/invocation/cmd/version.rs b/cli/src/invocation/cmd/version.rs
index 5c8c7577e..db3f2a80b 100644
--- a/cli/src/invocation/cmd/version.rs
+++ b/cli/src/invocation/cmd/version.rs
@@ -4,7 +4,7 @@ use termcolor::{ColorSpec, WriteColor};
 pub(crate) fn execute<W: WriteColor>(w: &mut W) -> Fallible<()> {
     write!(w, "TaskChampion ")?;
     w.set_color(ColorSpec::new().set_bold(true))?;
-    write!(w, "{}\n", env!("CARGO_PKG_VERSION"))?;
+    writeln!(w, "{}", env!("CARGO_PKG_VERSION"))?;
     w.reset()?;
     Ok(())
 }
diff --git a/cli/src/invocation/filter.rs b/cli/src/invocation/filter.rs
index e6eacc9fc..4bca65825 100644
--- a/cli/src/invocation/filter.rs
+++ b/cli/src/invocation/filter.rs
@@ -36,10 +36,7 @@ pub(super) fn filtered_tasks(
     let mut res = vec![];
 
     fn is_partial_uuid(taskid: &TaskId) -> bool {
-        match taskid {
-            TaskId::PartialUuid(_) => true,
-            _ => false,
-        }
+        matches!(taskid, TaskId::PartialUuid(_))
     }
 
     // We will enumerate the universe of tasks for this filter, checking
@@ -50,7 +47,7 @@ pub(super) fn filtered_tasks(
         Universe::IdList(ref ids) if ids.iter().any(is_partial_uuid) => {
             'task: for (uuid, task) in replica.all_tasks()?.drain() {
                 for id in ids {
-                    if match id {
+                    let in_universe = match id {
                         TaskId::WorkingSetId(id) => {
                             // NOTE: (#108) this results in many reads of the working set; it
                             // may be better to cache this information here or in the Replica.
@@ -58,11 +55,10 @@ pub(super) fn filtered_tasks(
                         }
                         TaskId::PartialUuid(prefix) => uuid.to_string().starts_with(prefix),
                         TaskId::Uuid(id) => id == &uuid,
-                    } {
-                        if match_task(filter, &task) {
-                            res.push(task);
-                            continue 'task;
-                        }
+                    };
+                    if in_universe && match_task(filter, &task) {
+                        res.push(task);
+                        continue 'task;
                     }
                 }
             }
diff --git a/cli/src/invocation/mod.rs b/cli/src/invocation/mod.rs
index 760be3964..1920bb2dc 100644
--- a/cli/src/invocation/mod.rs
+++ b/cli/src/invocation/mod.rs
@@ -17,6 +17,7 @@ use filter::filtered_tasks;
 use modify::apply_modification;
 
 /// Invoke the given Command in the context of the given settings
+#[allow(clippy::needless_return)]
 pub(crate) fn invoke(command: Command, settings: Config) -> Fallible<()> {
     log::debug!("command: {:?}", command);
     log::debug!("settings: {:?}", settings);
@@ -88,7 +89,7 @@ pub(crate) fn invoke(command: Command, settings: Config) -> Fallible<()> {
             subcommand: Subcommand::Version,
             ..
         } => unreachable!(),
-    }
+    };
 }
 
 // utilities for invoke
diff --git a/cli/src/invocation/modify.rs b/cli/src/invocation/modify.rs
index c3923f0ee..74b9b8d00 100644
--- a/cli/src/invocation/modify.rs
+++ b/cli/src/invocation/modify.rs
@@ -43,7 +43,7 @@ pub(super) fn apply_modification<W: WriteColor>(
         task.remove_tag(&tag)?;
     }
 
-    write!(w, "modified task {}\n", task.get_uuid())?;
+    writeln!(w, "modified task {}", task.get_uuid())?;
 
     Ok(())
 }
diff --git a/cli/src/lib.rs b/cli/src/lib.rs
index 01900fbc6..379b3ea81 100644
--- a/cli/src/lib.rs
+++ b/cli/src/lib.rs
@@ -1,3 +1,4 @@
+#![deny(clippy::all)]
 /*!
 This crate implements the command-line interface to TaskChampion.
 
diff --git a/cli/src/usage.rs b/cli/src/usage.rs
index d91b449cc..b8251ffd1 100644
--- a/cli/src/usage.rs
+++ b/cli/src/usage.rs
@@ -40,8 +40,8 @@ impl Usage {
             "TaskChampion {}: Personal task-tracking\n\n",
             env!("CARGO_PKG_VERSION")
         )?;
-        write!(w, "USAGE:\n  {} [args]\n\n", command_name)?;
-        write!(w, "TaskChampion subcommands:\n")?;
+        writeln!(w, "USAGE:\n  {} [args]\n", command_name)?;
+        writeln!(w, "TaskChampion subcommands:")?;
         for subcommand in self.subcommands.iter() {
             subcommand.write_help(&mut w, summary)?;
         }
@@ -58,7 +58,7 @@ impl Usage {
             modification.write_help(&mut w, summary)?;
         }
         if !summary {
-            write!(w, "\nSee `task help` for more detail\n")?;
+            writeln!(w, "\nSee `task help` for more detail")?;
         }
         Ok(())
     }
@@ -84,7 +84,7 @@ pub(crate) struct Subcommand {
 impl Subcommand {
     fn write_help<W: Write>(&self, mut w: W, summary: bool) -> Result<()> {
         if summary {
-            write!(w, "  task {} - {}\n", self.name, self.summary)?;
+            writeln!(w, "  task {} - {}", self.name, self.summary)?;
         } else {
             write!(
                 w,
diff --git a/sync-server/src/main.rs b/sync-server/src/main.rs
index 6c5fde701..c69ac6e77 100644
--- a/sync-server/src/main.rs
+++ b/sync-server/src/main.rs
@@ -1,3 +1,5 @@
+#![deny(clippy::all)]
+
 use crate::storage::{KVStorage, Storage};
 use actix_web::{get, web, App, HttpServer, Responder, Scope};
 use api::{api_scope, ServerState};
diff --git a/taskchampion/src/lib.rs b/taskchampion/src/lib.rs
index 715dcaefa..fb91f36e7 100644
--- a/taskchampion/src/lib.rs
+++ b/taskchampion/src/lib.rs
@@ -1,3 +1,4 @@
+#![deny(clippy::all)]
 /*!
 
 This crate implements the core of TaskChampion, the [replica](crate::Replica).
diff --git a/taskchampion/src/task.rs b/taskchampion/src/task.rs
index 2710a241c..8997919de 100644
--- a/taskchampion/src/task.rs
+++ b/taskchampion/src/task.rs
@@ -215,8 +215,8 @@ impl Task {
     /// Iterate over the task's tags
     pub fn get_tags(&self) -> impl Iterator<Item = Tag> + '_ {
         self.taskmap.iter().filter_map(|(k, _)| {
-            if k.starts_with("tag.") {
-                if let Ok(tag) = (&k[4..]).try_into() {
+            if let Some(tag) = k.strip_prefix("tag.") {
+                if let Ok(tag) = tag.try_into() {
                     return Some(tag);
                 }
                 // note that invalid "tag.*" are ignored
@@ -326,7 +326,7 @@ impl<'r> TaskMut<'r> {
 
         if let Some(v) = value {
             trace!("task {}: set property {}={:?}", self.task.uuid, property, v);
-            self.task.taskmap.insert(property.to_string(), v);
+            self.task.taskmap.insert(property, v);
         } else {
             trace!("task {}: remove property {}", self.task.uuid, property);
             self.task.taskmap.remove(&property);