diff --git a/lib/rivet/src/ast/Scope.ri b/lib/rivet/src/ast/Scope.ri
index e59d14bf0..343ea83fd 100644
--- a/lib/rivet/src/ast/Scope.ri
+++ b/lib/rivet/src/ast/Scope.ri
@@ -28,7 +28,7 @@ pub struct Scope {
 
     pub func add_or_get(mut self, sym: Sym) -> !Sym {
         if old_sym := self.find(sym.name) {
-            if sym is TypeSym as type_sym and old_sym is TypeSym as mut old_type_sym {
+            if sym is TypeSym(type_sym) and old_sym is TypeSym(mut old_type_sym) {
                 if old_type_sym.update(type_sym)! {
                     return old_sym;
                 }
@@ -117,7 +117,7 @@ pub struct Scope {
 
     pub func update_type(self, name: string, type: Type) {
         if sym := self.lookup(name) {
-            if sym is Var as var_info {
+            if sym is Var(var_info) {
                 var_info.type = type;
             }
         }
@@ -125,7 +125,7 @@ pub struct Scope {
 
     pub func update_is_hidden_ref(self, name: string, is_hidden_ref: bool) {
         if sym := self.lookup(name) {
-            if sym is Var as var_info {
+            if sym is Var(var_info) {
                 var_info.is_hidden_ref = is_hidden_ref;
             }
         }
@@ -133,7 +133,7 @@ pub struct Scope {
 
     pub func update_is_used(self, name: string, is_used: bool) {
         if sym := self.lookup(name) {
-            if sym is Var as var_info {
+            if sym is Var(var_info) {
                 var_info.is_used = is_used;
             }
         }
diff --git a/lib/rivet/src/ast/Sym.ri b/lib/rivet/src/ast/Sym.ri
index 3ecf23ea0..177f4475b 100644
--- a/lib/rivet/src/ast/Sym.ri
+++ b/lib/rivet/src/ast/Sym.ri
@@ -72,7 +72,7 @@ pub trait Sym {
     func module(self) -> ?Module {
         mut p := self;
         while {
-            if p is Module as mod {
+            if p is Module(mod) {
                 return mod;
             } else if p_ := p.parent {
                 p = p_;
diff --git a/lib/rivet/src/ast/TypeSym.ri b/lib/rivet/src/ast/TypeSym.ri
index 94711d798..8221ec1c5 100644
--- a/lib/rivet/src/ast/TypeSym.ri
+++ b/lib/rivet/src/ast/TypeSym.ri
@@ -93,12 +93,12 @@ pub struct TypeSym < Sym {
 
     #[inline]
     pub func find_func(self, name: string) -> ?Func {
-        return if sym := self.scope.find(name); sym is Func as func_ {
+        return if sym := self.scope.find(name); sym is Func(func_) {
             if self.info !is .Trait and !func_.has_body {
                 return none;
             }
             func_
-        } else if sym := self.find_in_base(name); sym is Func as func_ {
+        } else if sym := self.find_in_base(name); sym is Func(func_) {
             if self.info !is .Trait and !func_.has_body {
                 return none;
             }
diff --git a/tests/valid/src/traits.ri b/tests/valid/src/traits.ri
index 3a6184ae9..1df4a71c9 100644
--- a/tests/valid/src/traits.ri
+++ b/tests/valid/src/traits.ri
@@ -84,5 +84,5 @@ struct IntegerStruct {
 
 test "traits with `default_value` attribute" {
     is_ := IntegerStruct();
-    @assert(is_.i is IntegerValue as int_v and int_v.int == 5);
+    @assert(is_.i is IntegerValue(int_v) and int_v.int == 5);
 }