diff --git a/activesupport/lib/active_support/core_ext/string/conversions.rb b/activesupport/lib/active_support/core_ext/string/conversions.rb
index 29a88b07ad..e84a3909a1 100644
--- a/activesupport/lib/active_support/core_ext/string/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/string/conversions.rb
@@ -18,6 +18,7 @@ class String
   #   "2012-12-13T06:12".to_time         # => 2012-12-13 06:12:00 +0100
   #   "2012-12-13T06:12".to_time(:utc)   # => 2012-12-13 06:12:00 UTC
   #   "12/13/2012".to_time               # => ArgumentError: argument out of range
+  #   "1604326192".to_time               # => ArgumentError: argument out of range
   def to_time(form = :local)
     parts = Date._parse(self, false)
     used_keys = %i(year mon mday hour min sec sec_fraction offset)
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index f27a4423d3..cfde3a92bc 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -573,6 +573,14 @@ class StringConversionsTest < ActiveSupport::TestCase
     end
   end
 
+  def test_timestamp_string_to_time
+    exception = assert_raises(ArgumentError) do
+      "1604326192".to_time
+    end
+
+    assert_equal "argument out of range", exception.message
+  end
+
   def test_string_to_time_utc_offset
     with_env_tz "US/Eastern" do
       if ActiveSupport.to_time_preserves_timezone