diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index 99f1e33299d..351f97042d4 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -691,9 +691,9 @@ pub fn line_directive<'line>(
     }
 }
 
-/// This is generated by collecting directives from ui tests and then extracting their directive
-/// names. This is **not** an exhaustive list of all possible directives. Instead, this is a
-/// best-effort approximation for diagnostics.
+/// This was originally generated by collecting directives from ui tests and then extracting their
+/// directive names. This is **not** an exhaustive list of all possible directives. Instead, this is
+/// a best-effort approximation for diagnostics. Add new headers to this list when needed.
 const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     // tidy-alphabetical-start
     "assembly-output",
@@ -872,6 +872,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "only-unix",
     "only-wasm32",
     "only-wasm32-bare",
+    "only-wasm32-wasip1",
     "only-windows",
     "only-x86",
     "only-x86_64",