diff --git a/src/event.zig b/src/event.zig
index 319ed88..d6888bf 100644
--- a/src/event.zig
+++ b/src/event.zig
@@ -26,10 +26,11 @@ pub const SystemEvent = union(enum) {
     focus: bool,
 };
 
+/// Merge the two provided `union(enum)` `A` and `B` to a tagged union containing all fields of both tagged unions in `comptime`.
+/// Declarations are not supported for `comptime` created types, see https://github.com/ziglang/zig/issues/6709 for details.
 pub fn mergeTaggedUnions(comptime A: type, comptime B: type) type {
-    if (!isTaggedUnion(A) or !isTaggedUnion(B)) {
-        @compileError("Both types for merging tagged unions need to be of type `union(enum)`.");
-    }
+    if (!isTaggedUnion(A) or !isTaggedUnion(B)) @compileError("Both types for merging tagged unions need to be of type `union(enum)`.");
+
     const a_fields = @typeInfo(A).@"union".fields;
     const a_fields_tag = @typeInfo(A).@"union".tag_type.?;
     const a_enum_fields = @typeInfo(a_fields_tag).@"enum".fields;
@@ -54,6 +55,11 @@ pub fn mergeTaggedUnions(comptime A: type, comptime B: type) type {
         i += 1;
     }
 
+    // NOTE declarations are not supported for `comptime` types: https://github.com/ziglang/zig/issues/6709
+    // -> will lead to a compilation error when constructing the tagged union
+    //    at the end of this function in case at least one of the provided tagged
+    //    unions to merge contains declarations (which in this case can only be the
+    //    user provided one)
     const a_enum_decls = @typeInfo(A).@"union".decls;
     const b_enum_decls = @typeInfo(B).@"union".decls;
     var decls: [a_enum_decls.len + b_enum_decls.len]std.builtin.Type.Declaration = undefined;
@@ -67,11 +73,9 @@ pub fn mergeTaggedUnions(comptime A: type, comptime B: type) type {
         j += 1;
     }
 
-    const log2_i = @bitSizeOf(@TypeOf(i)) - @clz(i);
-
     const EventType = @Type(.{ .int = .{
         .signedness = .unsigned,
-        .bits = log2_i,
+        .bits = @bitSizeOf(@TypeOf(i)) - @clz(i),
     } });
 
     const Event = @Type(.{ .@"enum" = .{
@@ -89,13 +93,11 @@ pub fn mergeTaggedUnions(comptime A: type, comptime B: type) type {
     } });
 }
 
-// Determine at `comptime` whether the provided type `E` is an `union(enum)`.
-pub fn isTaggedUnion(comptime E: type) bool {
-    switch (@typeInfo(E)) {
-        .@"union" => |u| {
-            if (u.tag_type) |_| {} else {
-                return false;
-            }
+/// Determine at whether the provided type `T` is a tagged union: `union(enum)`.
+pub fn isTaggedUnion(comptime T: type) bool {
+    switch (@typeInfo(T)) {
+        .@"union" => |u| if (u.tag_type) |_| {} else {
+            return false;
         },
         else => return false,
     }