diff --git a/selfhost/cmd/w6a/main.combined.ww b/selfhost/cmd/w6a/main.combined.ww
index fabe6ba9..c528154f 100644
--- a/selfhost/cmd/w6a/main.combined.ww
+++ b/selfhost/cmd/w6a/main.combined.ww
@@ -3299,12 +3299,15 @@ export fn intern(a: *asm_, name: str) *asym = {
 };
 
 fn perr(a: *asm_, msg: str) void = {
-	os.write(2, "w6a: ".ptr, 4u64);
+	let pfx: str = "w6a: ";
+	os.write(2, pfx.ptr, pfx.len: u64);
 	let f: str = a.file;
 	os.write(2, f.ptr, f.len: u64);
-	os.write(2, ": ".ptr, 2u64);
+	let sep: str = ": ";
+	os.write(2, sep.ptr, sep.len: u64);
 	os.write(2, msg.ptr, msg.len: u64);
-	os.write(2, "\n".ptr, 1u64);
+	let nl: str = "\n";
+	os.write(2, nl.ptr, nl.len: u64);
 	a.errs += 1;
 };
 
diff --git a/selfhost/cmd/w6a/parse.ww b/selfhost/cmd/w6a/parse.ww
index 085c4751..dd11bf56 100644
--- a/selfhost/cmd/w6a/parse.ww
+++ b/selfhost/cmd/w6a/parse.ww
@@ -170,12 +170,15 @@ export fn intern(a: *asm_, name: str) *asym = {
 };
 
 fn perr(a: *asm_, msg: str) void = {
-	os.write(2, "w6a: ".ptr, 4u64);
+	let pfx: str = "w6a: ";
+	os.write(2, pfx.ptr, pfx.len: u64);
 	let f: str = a.file;
 	os.write(2, f.ptr, f.len: u64);
-	os.write(2, ": ".ptr, 2u64);
+	let sep: str = ": ";
+	os.write(2, sep.ptr, sep.len: u64);
 	os.write(2, msg.ptr, msg.len: u64);
-	os.write(2, "\n".ptr, 1u64);
+	let nl: str = "\n";
+	os.write(2, nl.ptr, nl.len: u64);
 	a.errs += 1;
 };