diff --git a/dsp/src/iir_int.rs b/dsp/src/iir_int.rs
index e3ec5b8..25c5b2f 100644
--- a/dsp/src/iir_int.rs
+++ b/dsp/src/iir_int.rs
@@ -96,7 +96,7 @@ impl IIR {
 
 #[cfg(test)]
 mod test {
-    use super::Vec5;
+    use super::{Vec5, Coeff};
 
     #[test]
     fn lowpass_gen() {