diff --git a/src/terminal/ansi.zig b/src/terminal/ansi.zig
index f34acf008..7cbd7d874 100644
--- a/src/terminal/ansi.zig
+++ b/src/terminal/ansi.zig
@@ -17,6 +17,10 @@ pub const C0 = enum(u7) {
     VT = 0x0B,
     /// Carriage return
     CR = 0x0D,
+    /// Shift out
+    SO = 0x0E,
+    /// Shift in
+    SI = 0x0F,
 };
 
 /// The SGR rendition aspects that can be set, sometimes known as attributes.
diff --git a/src/terminal/stream.zig b/src/terminal/stream.zig
index a07ca39a2..2958de0c0 100644
--- a/src/terminal/stream.zig
+++ b/src/terminal/stream.zig
@@ -67,6 +67,7 @@ pub fn Stream(comptime Handler: type) type {
         }
 
         fn execute(self: *Self, c: u8) !void {
+            // log.warn("C0: {}", .{c});
             switch (@intToEnum(ansi.C0, c)) {
                 .NUL => {},
 
@@ -100,6 +101,9 @@ pub fn Stream(comptime Handler: type) type {
                     try self.handler.carriageReturn()
                 else
                     log.warn("unimplemented execute: {x}", .{c}),
+
+                // TODO
+                .SO, .SI => log.warn("TODO: Shift out/Shift in", .{}),
             }
         }