diff --git a/src/apprt/gtk/version.zig b/src/apprt/gtk/version.zig
index 8d98f6a40..c470a872c 100644
--- a/src/apprt/gtk/version.zig
+++ b/src/apprt/gtk/version.zig
@@ -39,3 +39,20 @@ pub inline fn atLeast(
 
     return false;
 }
+
+test "atLeast" {
+    const std = @import("std");
+    const testing = std.testing;
+
+    try testing.expectEqual(true, atLeast(c.GTK_MAJOR_VERSION, c.GTK_MINOR_VERSION, c.GTK_MICRO_VERSION));
+
+    try testing.expectEqual(false, atLeast(c.GTK_MAJOR_VERSION, c.GTK_MINOR_VERSION, c.GTK_MICRO_VERSION + 1));
+    try testing.expectEqual(false, atLeast(c.GTK_MAJOR_VERSION, c.GTK_MINOR_VERSION + 1, c.GTK_MICRO_VERSION));
+    try testing.expectEqual(false, atLeast(c.GTK_MAJOR_VERSION + 1, c.GTK_MINOR_VERSION, c.GTK_MICRO_VERSION));
+
+    try testing.expectEqual(true, atLeast(c.GTK_MAJOR_VERSION - 1, c.GTK_MINOR_VERSION, c.GTK_MICRO_VERSION));
+    try testing.expectEqual(true, atLeast(c.GTK_MAJOR_VERSION - 1, c.GTK_MINOR_VERSION + 1, c.GTK_MICRO_VERSION));
+    try testing.expectEqual(true, atLeast(c.GTK_MAJOR_VERSION - 1, c.GTK_MINOR_VERSION, c.GTK_MICRO_VERSION + 1));
+
+    try testing.expectEqual(true, atLeast(c.GTK_MAJOR_VERSION, c.GTK_MINOR_VERSION - 1, c.GTK_MICRO_VERSION + 1));
+}