diff --git a/Sources/Parsing/Conversion.swift b/Sources/Parsing/Conversion.swift
index 6bc6500a4f..aac7c73773 100644
--- a/Sources/Parsing/Conversion.swift
+++ b/Sources/Parsing/Conversion.swift
@@ -26,3 +26,12 @@
   /// - Returns: An "un"-transformed input value.
   func unapply(_ output: Output) throws -> Input
 }
+
+extension Parse {
+  @inlinable
+  public init<Downstream>(
+    _ conversion: Downstream
+  ) where Parsers == Parsing.Parsers.MapConversion<Rest<Downstream.Input>, Downstream> {
+    self.init { Rest().map(conversion) }
+  }
+}