diff --git a/crates/fayalite/src/module.rs b/crates/fayalite/src/module.rs
index ac38ee8..144ca96 100644
--- a/crates/fayalite/src/module.rs
+++ b/crates/fayalite/src/module.rs
@@ -11,7 +11,7 @@ use crate::{
         ops::VariantAccess, Expr, Flow, Target, TargetBase, TargetPathArrayElement,
         TargetPathBundleField, TargetPathElement, ToExpr,
     },
-    int::{DynUInt, DynUIntType, FixedOrDynIntType, UInt},
+    int::{DynUInt, DynUIntType, FixedOrDynIntType, IntValue, UInt},
     intern::{Intern, Interned},
     memory::{Mem, MemBuilder, MemBuilderTarget, PortName},
     reg::Reg,
@@ -2259,8 +2259,10 @@ where
     ) -> RegBuilder<'a, (), (), ()> {
         self.reg_builder_with_loc(implicit_name.0, SourceLocation::caller())
     }
+    // intentionally takes Expr instead of impl ToExpr to help prevent
+    // `#[hdl] if a == b {}` instead of using `cmp_eq`
     #[track_caller]
-    pub fn if_<Ty>(&mut self, cond: impl ToExpr<Type = Ty>) -> IfScope
+    pub fn if_<Ty>(&mut self, cond: Expr<IntValue<Ty>>) -> IfScope
     where
         Ty: FixedOrDynIntType<
             1,
@@ -2273,7 +2275,7 @@ where
     }
     pub fn if_with_loc<Ty>(
         &mut self,
-        cond: impl ToExpr<Type = Ty>,
+        cond: Expr<IntValue<Ty>>,
         source_location: SourceLocation,
     ) -> IfScope
     where
@@ -2284,7 +2286,7 @@ where
             CanonicalValue = DynUInt,
         >,
     {
-        let cond = cond.to_expr().as_bool();
+        let cond = cond.as_bool();
         let outer_block = self.block_stack.top();
         let then_block = self.new_block();
         let else_block = self.new_block();