diff --git a/releasenotes.md b/releasenotes.md
index f058398fd..c4c6d3b0a 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -14,6 +14,7 @@
 - Hex escapes like `"\x80"` would be incorrectly lowered. #2623
 - Ignore const null check on deref in `$defined` and `$sizeof` #2633.
 - Subscripting of constant slices would sometimes be considered non-constant #2635.
+- Compiler crash when concatenating structs and arrays to an untyped list.
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.
diff --git a/src/compiler/sema_const.c b/src/compiler/sema_const.c
index 89b58c8bd..0adea99f9 100644
--- a/src/compiler/sema_const.c
+++ b/src/compiler/sema_const.c
@@ -425,9 +425,20 @@ bool sema_expr_analyse_ct_concat(SemaContext *context, Expr *concat_expr, Expr *
 					UNREACHABLE
 				case CONST_INIT_ARRAY_FULL:
 				{
+					Expr *el;
 					FOREACH(ConstInitializer *, val, init->init_array_full)
 					{
-						vec_add(untyped_exprs, val->init_value);
+						switch (val->kind)
+						{
+							case CONST_INIT_VALUE:
+								vec_add(untyped_exprs, val->init_value);
+								break;
+							default:
+								el = expr_new_expr(EXPR_CONST, single_expr);
+								expr_rewrite_const_initializer(el, val->type, val);
+								vec_add(untyped_exprs, el);
+								break;
+						}
 					}
 					continue;
 				}
diff --git a/test/test_suite/compile_time/concat_untyped_with_struct_array.c3t b/test/test_suite/compile_time/concat_untyped_with_struct_array.c3t
new file mode 100644
index 000000000..2a404e633
--- /dev/null
+++ b/test/test_suite/compile_time/concat_untyped_with_struct_array.c3t
@@ -0,0 +1,69 @@
+module assert_repro;
+import assert_repro::macros;
+
+struct ArrayEntry
+{
+    int x;
+}
+
+macro cause_assert()
+{
+    ArrayEntry[] $slice = {{1}, {2}, {3}};
+    $slice = macros::replace {ArrayEntry} ($slice, 0, {4});
+}
+
+fn int main()
+{
+    cause_assert();
+    return 0;
+}
+<*
+    This contains macros for working with arrays at compile time
+*>
+module assert_repro::macros { ValueT };
+alias SliceT = ValueT[];
+
+macro SliceT slice(SliceT $from, usz $start, usz $end = usz.max)
+{
+    $if $start >= $from.len:
+        return (SliceT){};
+    $else
+        $if $end >= $from.len:
+            return $from[$start..];
+        $else
+            return $from[$start..$end-1];
+        $endif
+    $endif
+}
+
+
+macro SliceT insert(SliceT $array, usz $position, ValueT $value)
+{
+    $if $position == $array.len:
+        return $array +++ {$value};
+    $else
+        $if $position == 0:
+            return {$value} +++ $array;
+        $else
+            return slice($array, 0, $position) +++ {$value} +++ slice($array, $position);
+        $endif
+    $endif
+}
+
+macro SliceT remove(SliceT $array, usz $position)
+{
+    $if $position == $array.len - 1:
+        return slice($array, 0, $array.len - 1);
+    $else
+        $if $position == 0:
+            return slice($array, 1);
+        $else
+            return slice($array, 0, $position) +++ slice($array, $position + 1);
+        $endif
+    $endif
+}
+
+macro SliceT replace(SliceT $array, usz $position, ValueT $value)
+{
+    return insert(remove($array,$position),$position,$value);
+}
\ No newline at end of file