diff --git a/glfw/src/main.zig b/glfw/src/main.zig
index b108b2b0..19357dd3 100644
--- a/glfw/src/main.zig
+++ b/glfw/src/main.zig
@@ -6,6 +6,7 @@ const c = @cImport(@cInclude("GLFW/glfw3.h"));
 pub const action = @import("action.zig");
 pub const hat = @import("hat.zig");
 pub const key = @import("key.zig");
+pub const mod = @import("mod.zig");
 pub const version = @import("version.zig");
 
 pub fn basicTest() void {
diff --git a/glfw/src/mod.zig b/glfw/src/mod.zig
new file mode 100644
index 00000000..4fd01e6a
--- /dev/null
+++ b/glfw/src/mod.zig
@@ -0,0 +1,23 @@
+//! Modifier key flags
+//!
+//! See glfw.SetKeyCallback for how these are used.
+
+const c = @cImport(@cInclude("GLFW/glfw3.h"));
+
+/// If this bit is set one or more Shift keys were held down.
+pub const shift = C.GLFW_MOD_SHIFT;
+
+/// If this bit is set one or more Control keys were held down.
+pub const control = C.GLFW_MOD_CONTROL;
+
+/// If this bit is set one or more Alt keys were held down.
+pub const alt = C.GLFW_MOD_ALT;
+
+/// If this bit is set one or more Super keys were held down.
+pub const super = C.GLFW_MOD_SUPER;
+
+/// If this bit is set the Caps Lock key is enabled and the glfw.lock_key_mods input mode is set.
+pub const caps_lock = C.GLFW_MOD_CAPS_LOCK;
+
+/// If this bit is set the Num Lock key is enabled and the glfw.lock_key_mods input mode is set.
+pub const num_lock = C.GLFW_MOD_NUM_LOCK;