diff --git a/src/Surface.zig b/src/Surface.zig
index 80d18f47e..c4516700d 100644
--- a/src/Surface.zig
+++ b/src/Surface.zig
@@ -142,7 +142,7 @@ const DerivedConfig = struct {
     confirm_close_surface: bool,
     mouse_interval: u64,
     macos_non_native_fullscreen: bool,
-    macos_option_as_alt: bool,
+    macos_option_as_alt: configpkg.OptionAsAlt,
 
     pub fn init(alloc_gpa: Allocator, config: *const configpkg.Config) !DerivedConfig {
         var arena = ArenaAllocator.init(alloc_gpa);
@@ -1042,9 +1042,11 @@ pub fn charCallback(
         // On macOS, we have to opt-in to using alt because option
         // by default is a unicode character sequence.
         if (comptime builtin.target.isDarwin()) {
-            if (!self.config.macos_option_as_alt) {
-                log.debug("macos_option_as_alt disabled, not sending esc prefix", .{});
-                break :alt;
+            switch (self.config.macos_option_as_alt) {
+                .false => break :alt,
+                .true => {},
+                .left => if (mods.sides.alt != .left) break :alt,
+                .right => if (mods.sides.alt != .right) break :alt,
             }
         }
 
diff --git a/src/apprt/embedded.zig b/src/apprt/embedded.zig
index 7c2f0514a..e9f2a403c 100644
--- a/src/apprt/embedded.zig
+++ b/src/apprt/embedded.zig
@@ -394,8 +394,16 @@ pub const Surface = struct {
         // then we strip the alt modifier from the mods for translation.
         const translate_mods = translate_mods: {
             var translate_mods = mods;
-            if (self.app.config.@"macos-option-as-alt")
-                translate_mods.alt = false;
+            switch (self.app.config.@"macos-option-as-alt") {
+                .false => {},
+                .true => translate_mods.alt = false,
+                .left => if (mods.sides.alt == .left) {
+                    translate_mods.alt = false;
+                },
+                .right => if (mods.sides.alt == .right) {
+                    translate_mods.alt = false;
+                },
+            }
 
             break :translate_mods translate_mods;
         };
diff --git a/src/config.zig b/src/config.zig
index b1e847153..773017a9a 100644
--- a/src/config.zig
+++ b/src/config.zig
@@ -249,7 +249,7 @@ pub const Config = struct {
     /// (i.e. alt+ctrl+a).
     ///
     /// This does not work with GLFW builds.
-    @"macos-option-as-alt": bool = false,
+    @"macos-option-as-alt": OptionAsAlt = .false,
 
     /// This is set by the CLI parser for deinit.
     _arena: ?ArenaAllocator = null,
@@ -1036,6 +1036,14 @@ fn equal(comptime T: type, old: T, new: T) bool {
     }
 }
 
+/// Valid values for macos-option-as-alt.
+pub const OptionAsAlt = enum {
+    false,
+    true,
+    left,
+    right,
+};
+
 /// Color represents a color using RGB.
 pub const Color = struct {
     r: u8,