Change the warning message prefix from "~" to "@"
diff --git a/lang/builtin/builtin.go b/lang/builtin/builtin.go
index 7e8c396..47de929 100644
--- a/lang/builtin/builtin.go
+++ b/lang/builtin/builtin.go
@@ -21,7 +21,7 @@
 
 var Statuses = [...]string{
 	// Warnings.
-	`"~end of data"`,
+	`"@end of data"`,
 
 	// Suspensions.
 	`"$short read"`,
diff --git a/release/c/wuffs-unsupported-snapshot.c b/release/c/wuffs-unsupported-snapshot.c
index 95b0c26..0f76610 100644
--- a/release/c/wuffs-unsupported-snapshot.c
+++ b/release/c/wuffs-unsupported-snapshot.c
@@ -4785,7 +4785,7 @@
     0x7FFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF,
 };
 
-const char* wuffs_base__warning__end_of_data = "~base: end of data";
+const char* wuffs_base__warning__end_of_data = "@base: end of data";
 const char* wuffs_base__suspension__short_read = "$base: short read";
 const char* wuffs_base__suspension__short_write = "$base: short write";
 const char* wuffs_base__error__bad_argument_length_too_short =
diff --git a/std/gif/decode_gif.wuffs b/std/gif/decode_gif.wuffs
index 383c8af..a6f8f65 100644
--- a/std/gif/decode_gif.wuffs
+++ b/std/gif/decode_gif.wuffs
@@ -228,7 +228,7 @@
 	// This is a new "if", not an "else", because the calls above can modify
 	// this.end_of_data.
 	if this.end_of_data {
-		return base."~end of data"
+		return base."@end of data"
 	}
 
 	blend = 0