diff --git a/acme/mail/src/util.c b/acme/mail/src/util.c
index c32de5feb..bbc87883c 100644
--- a/acme/mail/src/util.c
+++ b/acme/mail/src/util.c
@@ -88,7 +88,7 @@ error(char *fmt, ...)
 	va_end(arg);
 	fmtprint(&f, "\n");
 	fmtfdflush(&f);
-	threadexitsall(fmt);
+	threadexitsall(buf);
 }
 
 void
diff --git a/acme/news/src/util.c b/acme/news/src/util.c
index d3e6fdadc..86392f148 100644
--- a/acme/news/src/util.c
+++ b/acme/news/src/util.c
@@ -88,7 +88,7 @@ error(char *fmt, ...)
 	va_end(arg);
 	fmtprint(&f, "\n");
 	fmtfdflush(&f);
-	threadexitsall(fmt);
+	threadexitsall(buf);
 }
 
 void
diff --git a/acme/wiki/src/util.c b/acme/wiki/src/util.c
index 832d97321..144b15c7c 100644
--- a/acme/wiki/src/util.c
+++ b/acme/wiki/src/util.c
@@ -71,7 +71,7 @@ error(char *fmt, ...)
 	va_end(arg);
 	write(2, buf, n);
 	write(2, "\n", 1);
-	threadexitsall(fmt);
+	threadexitsall(buf);
 }
 
 void