diff --git a/src/terminal/stream.zig b/src/terminal/stream.zig
index 2c237fbb0..d9ec4c59b 100644
--- a/src/terminal/stream.zig
+++ b/src/terminal/stream.zig
@@ -73,6 +73,8 @@ pub const Action = union(Key) {
     reset_mode: Mode,
     save_mode: Mode,
     restore_mode: Mode,
+    request_mode: Mode,
+    request_mode_unknown: RawMode,
     modify_key_format: ansi.ModifyKeyFormat,
 
     pub const Key = lib.Enum(
@@ -121,6 +123,8 @@ pub const Action = union(Key) {
             "reset_mode",
             "save_mode",
             "restore_mode",
+            "request_mode",
+            "request_mode_unknown",
             "modify_key_format",
         },
     );
@@ -180,6 +184,11 @@ pub const Action = union(Key) {
             return @bitCast(self.mode);
         }
     };
+
+    pub const RawMode = extern struct {
+        mode: u16,
+        ansi: bool,
+    };
 };
 
 /// Returns a type that can process a stream of tty control characters.
@@ -1242,9 +1251,16 @@ pub fn Stream(comptime Handler: type) type {
                             break :decrqm;
                         }
 
-                        if (@hasDecl(T, "requestMode")) {
-                            try self.handler.requestMode(input.params[0], ansi_mode);
-                        } else log.warn("unimplemented DECRQM callback: {f}", .{input});
+                        const mode_raw = input.params[0];
+                        const mode = modes.modeFromInt(mode_raw, ansi_mode);
+                        if (mode) |m| {
+                            try self.handler.vt(.request_mode, .{ .mode = m });
+                        } else {
+                            try self.handler.vt(.request_mode_unknown, .{
+                                .mode = mode_raw,
+                                .ansi = ansi_mode,
+                            });
+                        }
                     },
 
                     else => log.warn(
diff --git a/src/termio/stream_handler.zig b/src/termio/stream_handler.zig
index cb78ff264..644613626 100644
--- a/src/termio/stream_handler.zig
+++ b/src/termio/stream_handler.zig
@@ -253,6 +253,8 @@ pub const StreamHandler = struct {
                 const v = self.terminal.modes.restore(value.mode);
                 try self.setMode(value.mode, v);
             },
+            .request_mode => try self.requestMode(value.mode),
+            .request_mode_unknown => try self.requestModeUnknown(value.mode, value.ansi),
             .modify_key_format => try self.setModifyKeyFormat(value),
         }
     }
@@ -456,22 +458,32 @@ pub const StreamHandler = struct {
         }
     }
 
-    pub fn requestMode(self: *StreamHandler, mode_raw: u16, ansi: bool) !void {
-        // Get the mode value and respond.
-        const code: u8 = code: {
-            const mode = terminal.modes.modeFromInt(mode_raw, ansi) orelse break :code 0;
-            if (self.terminal.modes.get(mode)) break :code 1;
-            break :code 2;
-        };
+    fn requestMode(self: *StreamHandler, mode: terminal.Mode) !void {
+        const tag: terminal.modes.ModeTag = @bitCast(@intFromEnum(mode));
+        const code: u8 = if (self.terminal.modes.get(mode)) 1 else 2;
 
         var msg: termio.Message = .{ .write_small = .{} };
         const resp = try std.fmt.bufPrint(
             &msg.write_small.data,
             "\x1B[{s}{};{}$y",
+            .{
+                if (tag.ansi) "" else "?",
+                tag.value,
+                code,
+            },
+        );
+        msg.write_small.len = @intCast(resp.len);
+        self.messageWriter(msg);
+    }
+
+    fn requestModeUnknown(self: *StreamHandler, mode_raw: u16, ansi: bool) !void {
+        var msg: termio.Message = .{ .write_small = .{} };
+        const resp = try std.fmt.bufPrint(
+            &msg.write_small.data,
+            "\x1B[{s}{};0$y",
             .{
                 if (ansi) "" else "?",
                 mode_raw,
-                code,
             },
         );
         msg.write_small.len = @intCast(resp.len);