diff --git a/Cargo.lock b/Cargo.lock
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10,6 +10,7 @@
  "futures-util",
  "itertools",
  "itoa",
+ "static_assertions",
  "thiserror",
  "tokio",
  "tokio-serial",
@@ -274,6 +275,12 @@
  "libc",
  "windows-sys 0.61.2",
 ]
+
+[[package]]
+name = "static_assertions"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
 [[package]]
 name = "syn"
diff --git a/crates/arctictis/Cargo.toml b/crates/arctictis/Cargo.toml
--- a/crates/arctictis/Cargo.toml
+++ b/crates/arctictis/Cargo.toml
@@ -15,6 +15,7 @@
 
 [dev-dependencies]
 claims.workspace = true
+static_assertions = "1.1.0"
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 
 [lints]
diff --git a/crates/arctictis/src/macros.rs b/crates/arctictis/src/macros.rs
--- a/crates/arctictis/src/macros.rs
+++ b/crates/arctictis/src/macros.rs
@@ -274,8 +274,12 @@
 mod tests {
     use claims::{assert_err_eq, assert_ok_eq};
     use itertools::Itertools;
+    use static_assertions::assert_type_eq_all;
 
-    use crate::command::{Command, NoParams, Response, SingleParam};
+    use crate::{
+        OkResponse,
+        command::{Command, NoParams, Response, SingleParam},
+    };
 
     #[test]
     fn many_fields() {
@@ -304,7 +308,7 @@
 
         assert_eq!(Set::TEXT, b"TXT");
         assert_eq!(Set(fields.clone()).params(), fields);
-        assert_eq!(<Set as Command>::Response::expected_field_count(), 1);
+        assert_type_eq_all!(<Set as Command>::Response, OkResponse);
 
         assert_eq!(
             fields.clone().into_iter().map(|b| b.to_vec()).collect_vec(),
@@ -319,8 +323,6 @@
             Fields::deserialize(helper::build_response(&[b"1", b"20"]).iter()),
             FieldsError("field2"),
         );
-
-        // TODO: static type assertions
     }
 
     #[test]
@@ -341,7 +343,7 @@
 
         assert_eq!(Set::TEXT, b"TXT");
         assert_eq!(Set(Field(1)).params(), SingleParam(Field(1)));
-        assert_eq!(<Set as Command>::Response::expected_field_count(), 1);
+        assert_type_eq_all!(<Set as Command>::Response, OkResponse);
 
         // serialization handled by `SingleParam`
 
@@ -364,8 +366,7 @@
 
         assert_eq!(Get::TEXT, b"TXT");
         assert_eq!(Get(Field(1)).params(), SingleParam(Field(1)));
-        assert_eq!(<Get as Command>::Response::expected_field_count(), 1);
-        // TODO: static type assertions
+        assert_type_eq_all!(<Get as Command>::Response, Field);
     }
 
     mod helper {