diff --git a/.changeset/wicked-apples-press.md b/.changeset/wicked-apples-press.md
new file mode 100644
index 00000000000..5b4cb423315
--- /dev/null
+++ b/.changeset/wicked-apples-press.md
@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+Prevent Effect.if from crashing when first argument is not an Effect
diff --git a/packages/effect/src/internal/core.ts b/packages/effect/src/internal/core.ts
index 9a2fe50c234..fffd2f6119c 100644
--- a/packages/effect/src/internal/core.ts
+++ b/packages/effect/src/internal/core.ts
@@ -952,7 +952,8 @@ export const if_ = dual<
   (self: boolean | Effect.Effect<unknown, unknown, unknown>, { onFalse, onTrue }: {
     readonly onTrue: Effect.Effect<unknown, unknown, unknown>
     readonly onFalse: Effect.Effect<unknown, unknown, unknown>
-  }) => typeof self === "boolean" ? (self ? onTrue : onFalse) : flatMap(self, (b) => (b ? onTrue : onFalse))
+    // eslint-disable-next-line no-extra-boolean-cast
+  }) => isEffect(self) ? flatMap(self, (b) => (b ? onTrue : onFalse)) : Boolean(self) ? onTrue : onFalse
 )
 
 /* @internal */