diff --git a/api-test/src/schema/string_list.rs b/api-test/src/schema/string_list.rs
index 3aac603d..19608bac 100644
--- a/api-test/src/schema/string_list.rs
+++ b/api-test/src/schema/string_list.rs
@@ -62,9 +62,7 @@ impl<'de> serde::de::Visitor<'de> for StringListVisitor {
     }
 
     fn visit_seq<A: serde::de::SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
-        let mut out = seq
-            .size_hint()
-            .map_or_else(Vec::new, |size| Vec::with_capacity(size));
+        let mut out = seq.size_hint().map_or_else(Vec::new, Vec::with_capacity);
         loop {
             match seq.next_element::<String>()? {
                 Some(el) => out.push(el),
diff --git a/api-test/src/schema/string_set.rs b/api-test/src/schema/string_set.rs
index 891287ec..20133e4d 100644
--- a/api-test/src/schema/string_set.rs
+++ b/api-test/src/schema/string_set.rs
@@ -13,7 +13,7 @@ pub trait ForEachStr {
         F: FnMut(&str) -> Result<(), Error>;
 }
 
-impl ForEachStr for HashSet<String> {
+impl<S: std::hash::BuildHasher> ForEachStr for HashSet<String, S> {
     fn for_each_str<F>(&self, mut func: F) -> Result<(), Error>
     where
         F: FnMut(&str) -> Result<(), Error>,
@@ -69,7 +69,7 @@ impl<'de> serde::de::Visitor<'de> for StringSetVisitor {
     fn visit_seq<A: serde::de::SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
         let mut out = seq
             .size_hint()
-            .map_or_else(HashSet::new, |size| HashSet::with_capacity(size));
+            .map_or_else(HashSet::new, HashSet::with_capacity);
         loop {
             match seq.next_element::<String>()? {
                 Some(el) => out.insert(el),
diff --git a/api-test/src/schema/tools.rs b/api-test/src/schema/tools.rs
index 376ea2e3..83376698 100644
--- a/api-test/src/schema/tools.rs
+++ b/api-test/src/schema/tools.rs
@@ -39,13 +39,13 @@ impl StringContainer for Option<Vec<String>> {
     }
 }
 
-impl StringContainer for HashSet<String> {
+impl<S: std::hash::BuildHasher> StringContainer for HashSet<String, S> {
     fn all<F: Fn(&str) -> bool>(&self, pred: F) -> bool {
         self.iter().all(|s| pred(s))
     }
 }
 
-impl StringContainer for Option<HashSet<String>> {
+impl<S: std::hash::BuildHasher> StringContainer for Option<HashSet<String, S>> {
     fn all<F: Fn(&str) -> bool>(&self, pred: F) -> bool {
         self.as_ref()
             .map(|c| StringContainer::all(c, pred))