diff --git a/jerry-core/ecma/operations/ecma-comparison.c b/jerry-core/ecma/operations/ecma-comparison.c
index fe097c82b..3699fe252 100644
--- a/jerry-core/ecma/operations/ecma-comparison.c
+++ b/jerry-core/ecma/operations/ecma-comparison.c
@@ -151,16 +151,6 @@ ecma_op_abstract_equality_compare (ecma_value_t x, /**< first operand */
     return ecma_op_abstract_equality_compare (ecma_make_integer_value (ecma_is_value_true (x) ? 1 : 0), y);
   }
 
-  if (ecma_is_value_undefined (x)
-      || ecma_is_value_null (x))
-  {
-    /* 1. a., b. */
-    /* 2., 3. */
-    bool is_equal = ecma_is_value_undefined (y) || ecma_is_value_null (y);
-
-    return ecma_make_boolean_value (is_equal);
-  }
-
 #if ENABLED (JERRY_BUILTIN_BIGINT)
   if (JERRY_UNLIKELY (ecma_is_value_bigint (x)))
   {
@@ -199,6 +189,16 @@ ecma_op_abstract_equality_compare (ecma_value_t x, /**< first operand */
   }
 #endif /* ENABLED (JERRY_BUILTIN_BIGINT) */
 
+  if (ecma_is_value_undefined (x)
+      || ecma_is_value_null (x))
+  {
+    /* 1. a., b. */
+    /* 2., 3. */
+    bool is_equal = ecma_is_value_undefined (y) || ecma_is_value_null (y);
+
+    return ecma_make_boolean_value (is_equal);
+  }
+
 #if ENABLED (JERRY_ESNEXT)
   if (JERRY_UNLIKELY (ecma_is_value_symbol (x)))
   {
diff --git a/tests/jerry/es.next/regression-test-issue-4139.js b/tests/jerry/es.next/regression-test-issue-4139.js
new file mode 100644
index 000000000..6f176f495
--- /dev/null
+++ b/tests/jerry/es.next/regression-test-issue-4139.js
@@ -0,0 +1,16 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var b;
+assert(0n !== b);