diff --git a/system/Helpers/form_helper.php b/system/Helpers/form_helper.php
index 82c809ce3fa4..7f39ebe03bc8 100644
--- a/system/Helpers/form_helper.php
+++ b/system/Helpers/form_helper.php
@@ -839,7 +839,7 @@ function set_checkbox(string $field, string $value = '', bool $default = false):
 		}
 
 		// Unchecked checkbox and radio inputs are not even submitted by browsers ...
-		if (! empty($request->getPost()) || ! empty(old($field)))
+		if (intval($input) === 0 || ! empty($request->getPost()) || ! empty(old($field)))
 		{
 			return ($input === $value) ? ' checked="checked"' : '';
 		}
@@ -891,7 +891,7 @@ function set_radio(string $field, string $value = '', bool $default = false): st
 
 		// Unchecked checkbox and radio inputs are not even submitted by browsers ...
 		$result = '';
-		if (! empty($input = $request->getPost($field)) || ! empty($input = old($field)))
+		if (intval($input) === 0 || ! empty($input = $request->getPost($field)) || ! empty($input = old($field)))
 		{
 			$result = ($input === $value) ? ' checked="checked"' : '';
 		}
diff --git a/tests/system/Helpers/FormHelperTest.php b/tests/system/Helpers/FormHelperTest.php
index 6df61f4ea2cf..7d5c96ba1678 100644
--- a/tests/system/Helpers/FormHelperTest.php
+++ b/tests/system/Helpers/FormHelperTest.php
@@ -724,6 +724,33 @@ public function testSetCheckbox()
 		$this->assertEquals('', set_checkbox('foo', 'bar'));
 	}
 
+	// ------------------------------------------------------------------------
+	public function testSetCheckboxWithValueZero()
+	{
+		$_SESSION = [
+			'_ci_old_input' => [
+				'post' => [
+					'foo' => '0',
+				],
+			],
+		];
+
+		$this->assertEquals(' checked="checked"', set_checkbox('foo', '0'));
+
+		$_SESSION = [
+			'_ci_old_input' => [
+				'post' => [
+					'foo' => ['foo' => '0'],
+				],
+			],
+		];
+		$this->assertEquals(' checked="checked"', set_checkbox('foo', '0'));
+		$this->assertEquals('', set_checkbox('foo', 'baz'));
+
+		$_SESSION = [];
+		$this->assertEquals('', set_checkbox('foo', 'bar'));
+	}
+
 	// ------------------------------------------------------------------------
 	/**
 	 * @runInSeparateProcess
@@ -755,6 +782,17 @@ public function testSetRadioFromPost()
 		$this->assertEquals('', set_radio('bar', 'boop'));
 	}
 
+	/**
+	 * @runInSeparateProcess
+	 * @preserveGlobalState  disabled
+	 */
+	public function testSetRadioFromPostWithValueZero()
+	{
+		$_POST['bar'] = 0;
+		$this->assertEquals(' checked="checked"', set_radio('bar', '0'));
+		$this->assertEquals('', set_radio('bar', 'boop'));
+	}
+
 	public function testSetRadioFromPostArray()
 	{
 		$_SESSION = [
@@ -771,6 +809,22 @@ public function testSetRadioFromPostArray()
 		$this->assertEquals('', set_radio('bar', 'baz'));
 	}
 
+	public function testSetRadioFromPostArrayWithValueZero()
+	{
+		$_SESSION = [
+			'_ci_old_input' => [
+				'post' => [
+					'bar' => [
+						'0',
+						'fuzzy',
+					],
+				],
+			],
+		];
+		$this->assertEquals(' checked="checked"', set_radio('bar', '0'));
+		$this->assertEquals('', set_radio('bar', 'baz'));
+	}
+
 	public function testSetRadioDefault()
 	{
 		$this->assertEquals(' checked="checked"', set_radio('code', 'alpha', true));