diff --git a/builtins/array.c b/builtins/array.c
index a615a80..4f9070f 100644
--- a/builtins/array.c
+++ b/builtins/array.c
@@ -228,6 +228,33 @@ public array_t Array__slice(array_t *array, int64_t first, int64_t stride, int64
     };
 }
 
+array_t Array__concat(array_t *x, array_t *y, const TypeInfo *type)
+{
+    int64_t item_size = get_item_size(type);
+    void *data = x->atomic ? GC_MALLOC_ATOMIC(item_size*(x->length + y->length)) : GC_MALLOC(item_size*(x->length + y->length));
+    if (x->stride == item_size) {
+        memcpy(data, x->data, item_size*x->length);
+    } else {
+        for (int64_t i = 0; i < x->length; i++)
+            memcpy(data + i*item_size, x->data + i*item_size, item_size);
+    }
+
+    if (y->stride == item_size) {
+        memcpy(data + item_size*x->length, y->data, item_size*y->length);
+    } else {
+        for (int64_t i = 0; i < x->length; i++)
+            memcpy(data + (x->length + i)*item_size, y->data + i*item_size, item_size);
+    }
+
+    return (array_t){
+        .data=data,
+        .length=x->length + y->length,
+        .stride=item_size,
+        .copy_on_write=0,
+        .atomic=x->atomic,
+    };
+}
+
 public bool Array__contains(array_t array, void *item, const TypeInfo *type)
 {
     TypeInfo *item_type = type->ArrayInfo.item;
diff --git a/builtins/array.h b/builtins/array.h
index 65b7028..5a4b29a 100644
--- a/builtins/array.h
+++ b/builtins/array.h
@@ -32,6 +32,7 @@ void Array__clear(array_t *array, const TypeInfo *type);
 void Array__compact(array_t *arr, const TypeInfo *type);
 bool Array__contains(array_t array, void *item, const TypeInfo *type);
 array_t Array__slice(array_t *array, int64_t first, int64_t stride, int64_t length, bool readonly, const TypeInfo *type);
+array_t Array__concat(array_t *x, array_t *y, const TypeInfo *type);
 uint32_t Array__hash(const array_t *arr, const TypeInfo *type);
 int32_t Array__compare(const array_t *x, const array_t *y, const TypeInfo *type);
 bool Array__equal(const array_t *x, const array_t *y, const TypeInfo *type);
diff --git a/compile.c b/compile.c
index 8db7240..0690880 100644
--- a/compile.c
+++ b/compile.c
@@ -314,9 +314,7 @@ CORD compile(env_t *env, ast_t *ast)
                 return CORD_all("CORD_cat(", lhs, ", ", rhs, ")");
             }
             case ArrayType: {
-                return CORD_all("({ array_t $joined = ", lhs, ", $rhs = ", rhs, ";\n"
-                                "Array__insert_all(&$joined, $rhs, 0, ", compile_type_info(env, operand_t), ");\n"
-                                "$joined; })");
+                return CORD_all("Array__concat(", lhs, ", ", rhs, ", ", compile_type_info(env, operand_t), ")");
             }
             default:
                 code_err(ast, "Concatenation isn't supported for %T types", operand_t);
@@ -375,6 +373,14 @@ CORD compile(env_t *env, ast_t *ast)
                 code_err(ast, "'or=' is not implemented for %T types", operand_t);
         }
         case BINOP_XOR: return CORD_asprintf("%r ^= %r;", lhs, rhs);
+        case BINOP_CONCAT: {
+            if (operand_t->tag == StringType)
+                return CORD_asprintf("%r = CORD_cat(%r, %r);", lhs, lhs, rhs);
+            else if (operand_t->tag == ArrayType)
+                return CORD_all(lhs, "Array__concat(", lhs, ", ", rhs, ", ", compile_type_info(env, operand_t), ")");
+            else
+                code_err(ast, "'++=' is not implemented for %T types", operand_t);
+        }
         default: code_err(ast, "Update assignments are not implemented for this operation");
         }
     }