diff --git a/Cargo.toml b/Cargo.toml
index 9fba627c..8f4a214d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,10 +29,13 @@ indexmap = "1.9.1"
 libdeflater = "0.11.0"
 log = "0.4.17"
 stderrlog = { version = "0.5.3", optional = true, default-features = false }
-crossbeam-channel = "0.5.6"
 bitvec = "1.0.1"
 rustc-hash = "1.1.0"
 
+[dependencies.crossbeam-channel]
+optional = true
+version = "0.5.6"
+
 [dependencies.filetime]
 optional = true
 version = "0.2.17"
@@ -60,7 +63,7 @@ rustc_version = "0.4.0"
 [features]
 binary = ["clap", "wild", "stderrlog"]
 default = ["binary", "filetime", "parallel", "zopfli"]
-parallel = ["rayon", "indexmap/rayon"]
+parallel = ["rayon", "indexmap/rayon", "crossbeam-channel"]
 freestanding = ["libdeflater/freestanding"]
 
 [lib]
diff --git a/tests/flags.rs b/tests/flags.rs
index 6ff0ee85..38db85b7 100644
--- a/tests/flags.rs
+++ b/tests/flags.rs
@@ -4,6 +4,7 @@ use oxipng::{InFile, OutFile};
 #[cfg(feature = "filetime")]
 use std::cell::RefCell;
 use std::fs::remove_file;
+#[cfg(feature = "zopfli")]
 use std::num::NonZeroU8;
 #[cfg(feature = "filetime")]
 use std::ops::Deref;
@@ -95,9 +96,12 @@ fn test_it_converts(
 
 #[test]
 fn verbose_mode() {
+    #[cfg(feature = "parallel")]
     use crossbeam_channel::{unbounded, Sender};
     use log::{set_logger, set_max_level, Level, LevelFilter, Log, Metadata, Record};
     use std::cell::RefCell;
+    #[cfg(not(feature = "parallel"))]
+    use std::sync::mpsc::{channel as unbounded, Sender};
 
     // Rust runs tests in parallel by default.
     // We want to make sure that we verify only logs from our test.
@@ -169,7 +173,7 @@ fn verbose_mode() {
         thread_exec();
     });
 
-    let mut logs: Vec<_> = receiver.into_iter().collect();
+    let logs: Vec<_> = receiver.into_iter().collect();
     println!("logs={:?}", logs);
     assert_eq!(logs.len(), 9);
     let expected_logs = [