diff --git a/src/btor2/serialize.rs b/src/btor2/serialize.rs
index 66dc50c..0ff9969 100644
--- a/src/btor2/serialize.rs
+++ b/src/btor2/serialize.rs
@@ -3,10 +3,11 @@
 // author: Kevin Laeufer <laeufer@berkeley.edu>
 
 use crate::ir::*;
+use std::io::Write;
 
 pub fn serialize(
     ctx: &Context,
-    writer: &mut impl (std::io::Write),
+    writer: &mut impl Write,
     sys: &TransitionSystem,
 ) -> std::io::Result<()> {
     Serializer::new(ctx, writer).serialize_sys(sys)
@@ -20,12 +21,12 @@ pub fn serialize_to_str(ctx: &Context, sys: &TransitionSystem) -> String {
     String::from_utf8(buf).expect("Failed to read string we wrote!")
 }
 
-struct Serializer<'a, W: std::io::Write> {
+struct Serializer<'a, W: Write> {
     ctx: &'a Context,
     writer: &'a mut W,
 }
 
-impl<'a, W: std::io::Write> Serializer<'a, W> {
+impl<'a, W: Write> Serializer<'a, W> {
     fn new(ctx: &'a Context, writer: &'a mut W) -> Self {
         Serializer { ctx, writer }
     }
diff --git a/tests/btor2_test.rs b/tests/btor2_test.rs
index 3f3a1e3..59244ef 100644
--- a/tests/btor2_test.rs
+++ b/tests/btor2_test.rs
@@ -27,9 +27,22 @@ fn parse_count2() {
     insta::assert_snapshot!(sys.serialize_to_str(&ctx));
 }
 
+#[test]
+fn serialize_count2() {
+    let mut ctx = Context::default();
+    let sys = btor2::parse_str(&mut ctx, COUNT_2, Some("count2")).unwrap();
+    insta::assert_snapshot!(btor2::serialize_to_str(&ctx, &sys));
+}
+
 
 #[test]
 fn parse_quiz1() {
     let (ctx, sys) = btor2::parse_file("inputs/Quiz1.btor").unwrap();
     insta::assert_snapshot!(sys.serialize_to_str(&ctx));
+}
+
+#[test]
+fn serialize_quiz1() {
+    let (ctx, sys) = btor2::parse_file("inputs/Quiz1.btor").unwrap();
+    insta::assert_snapshot!(btor2::serialize_to_str(&ctx, &sys));
 }
\ No newline at end of file
diff --git a/tests/snapshots/btor2_test__serialize_count2.snap b/tests/snapshots/btor2_test__serialize_count2.snap
new file mode 100644
index 0000000..73b3e4e
--- /dev/null
+++ b/tests/snapshots/btor2_test__serialize_count2.snap
@@ -0,0 +1,6 @@
+---
+source: tests/btor2_test.rs
+expression: "btor2::serialize_to_str(&ctx, &sys)"
+---
+; btor2 description of `count2` generated by patron 0.2.0
+
diff --git a/tests/snapshots/btor2_test__serialize_quiz1.snap b/tests/snapshots/btor2_test__serialize_quiz1.snap
new file mode 100644
index 0000000..4d6ee42
--- /dev/null
+++ b/tests/snapshots/btor2_test__serialize_quiz1.snap
@@ -0,0 +1,6 @@
+---
+source: tests/btor2_test.rs
+expression: "btor2::serialize_to_str(&ctx, &sys)"
+---
+; btor2 description of `Quiz1` generated by patron 0.2.0
+