diff --git a/src/termio.zig b/src/termio.zig
index b2c2c1a63..d151e46dd 100644
--- a/src/termio.zig
+++ b/src/termio.zig
@@ -7,6 +7,7 @@ pub const reader = @import("termio/reader.zig");
 pub const Options = @import("termio/Options.zig");
 pub const Termio = @import("termio/Termio.zig");
 pub const Thread = @import("termio/Thread.zig");
+pub const DerivedConfig = Termio.DerivedConfig;
 pub const Mailbox = Thread.Mailbox;
 
 test {
diff --git a/src/termio/Termio.zig b/src/termio/Termio.zig
index f1c500f0a..432ce158b 100644
--- a/src/termio/Termio.zig
+++ b/src/termio/Termio.zig
@@ -378,13 +378,7 @@ pub fn changeConfig(self: *Termio, td: *ThreadData, config: *DerivedConfig) !voi
     // renderer mutex so this is safe to do despite being executed
     // from another thread.
     td.ev.terminal_stream.handler.changeConfig(&self.config);
-    switch (td.reader) {
-        .manual => {},
-        .exec => |*exec| {
-            exec.abnormal_runtime_threshold_ms = config.abnormal_runtime_threshold_ms;
-            exec.wait_after_command = config.wait_after_command;
-        },
-    }
+    td.reader.changeConfig(&self.config);
 
     // Update the configuration that we know about.
     //
diff --git a/src/termio/reader.zig b/src/termio/reader.zig
index b83083030..99f78b561 100644
--- a/src/termio/reader.zig
+++ b/src/termio/reader.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const configpkg = @import("../config.zig");
+const termio = @import("../termio.zig");
 const Command = @import("../Command.zig");
 
 /// The kinds of readers.
@@ -45,4 +46,14 @@ pub const ThreadData = union(Kind) {
         /// to close the surface.
         wait_after_command: bool,
     },
+
+    pub fn changeConfig(self: *ThreadData, config: *termio.DerivedConfig) void {
+        switch (self.*) {
+            .manual => {},
+            .exec => |*exec| {
+                exec.abnormal_runtime_threshold_ms = config.abnormal_runtime_threshold_ms;
+                exec.wait_after_command = config.wait_after_command;
+            },
+        }
+    }
 };