diff --git a/juniper_codegen/Cargo.toml b/juniper_codegen/Cargo.toml
index 07bd7787..92fbb492 100644
--- a/juniper_codegen/Cargo.toml
+++ b/juniper_codegen/Cargo.toml
@@ -21,7 +21,7 @@ proc-macro = true
 proc-macro-error = "1.0.2"
 proc-macro2 = "1.0.1"
 quote = "1.0.3"
-syn = { version = "1.0.60", features = ["extra-traits", "full", "parsing", "visit", "visit-mut"], default-features = false }
+syn = { version = "1.0.90", features = ["extra-traits", "full", "parsing", "visit", "visit-mut"], default-features = false }
 url = "2.0"
 
 [dev-dependencies]
diff --git a/juniper_codegen/src/common/parse/mod.rs b/juniper_codegen/src/common/parse/mod.rs
index 5781a623..05e4b860 100644
--- a/juniper_codegen/src/common/parse/mod.rs
+++ b/juniper_codegen/src/common/parse/mod.rs
@@ -208,12 +208,10 @@ impl TypeExt for syn::Type {
             T::BareFn(_) | T::Infer(_) | T::Macro(_) | T::Never(_) | T::Verbatim(_) => {}
 
             // Following the syn idiom for exhaustive matching on Type:
-            // https://github.com/dtolnay/syn/blob/master/src/ty.rs#L66-L88
-            #[cfg(test)]
-            T::__TestExhaustive(_) => unimplemented!(),
-
-            #[cfg(not(test))]
-            _ => {}
+            // https://github.com/dtolnay/syn/blob/1.0.90/src/ty.rs#L67-L87
+            // TODO: #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))]
+            //       https://github.com/rust-lang/rust/issues/89554
+            _ => unimplemented!(),
         }
     }