diff --git a/src/functions.php b/src/functions.php
index cad88a2..865f6b9 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -104,13 +104,27 @@
  */
 function append($stream, $callback, $read_write = STREAM_FILTER_ALL)
 {
-    $ret = @\stream_filter_append($stream, register(), $read_write, $callback);
+    $errstr = '';
+    \set_error_handler(function ($_, $error) use (&$errstr) {
+        // Match errstr from PHP's warning message.
+        // stream_filter_append() expects parameter 1 to be resource,...
+        $errstr = $error; // @codeCoverageIgnore
+    });
+
+    try {
+        $ret = \stream_filter_append($stream, register(), $read_write, $callback);
+    } catch (\TypeError $e) { // @codeCoverageIgnoreStart
+        // Throws TypeError on PHP 8.0+
+        \restore_error_handler();
+        throw $e;
+    } // @codeCoverageIgnoreEnd
+
+    \restore_error_handler();
 
     // PHP 8 throws above on type errors, older PHP and memory issues can throw here
     // @codeCoverageIgnoreStart
     if ($ret === false) {
-        $error = \error_get_last() + array('message' => '');
-        throw new \RuntimeException('Unable to append filter: ' . $error['message']);
+        throw new \RuntimeException('Unable to append filter: ' . $errstr);
     }
     // @codeCoverageIgnoreEnd
 
@@ -147,13 +161,27 @@ function append($stream, $callback, $read_write = STREAM_FILTER_ALL)
  */
 function prepend($stream, $callback, $read_write = STREAM_FILTER_ALL)
 {
-    $ret = @\stream_filter_prepend($stream, register(), $read_write, $callback);
+    $errstr = '';
+    \set_error_handler(function ($_, $error) use (&$errstr) {
+        // Match errstr from PHP's warning message.
+        // stream_filter_prepend() expects parameter 1 to be resource,...
+        $errstr = $error; // @codeCoverageIgnore
+    });
+
+    try {
+        $ret = \stream_filter_prepend($stream, register(), $read_write, $callback);
+    } catch (\TypeError $e) { // @codeCoverageIgnoreStart
+        // Throws TypeError on PHP 8.0+
+        \restore_error_handler();
+        throw $e;
+    } // @codeCoverageIgnoreEnd
+
+    \restore_error_handler();
 
     // PHP 8 throws above on type errors, older PHP and memory issues can throw here
     // @codeCoverageIgnoreStart
     if ($ret === false) {
-        $error = \error_get_last() + array('message' => '');
-        throw new \RuntimeException('Unable to prepend filter: ' . $error['message']);
+        throw new \RuntimeException('Unable to prepend filter: ' . $errstr);
     }
     // @codeCoverageIgnoreEnd
 
@@ -242,16 +270,25 @@ function prepend($stream, $callback, $read_write = STREAM_FILTER_ALL)
 function fun($filter, $parameters = null)
 {
     $fp = \fopen('php://memory', 'w');
+
+    $errstr = '';
+    \set_error_handler(function ($_, $error) use (&$errstr) {
+        // Match errstr from PHP's warning message.
+        // stream_filter_append() expects parameter 1 to be resource,...
+        $errstr = $error;
+    });
+
     if (\func_num_args() === 1) {
-        $filter = @\stream_filter_append($fp, $filter, \STREAM_FILTER_WRITE);
+        $filter = \stream_filter_append($fp, $filter, \STREAM_FILTER_WRITE);
     } else {
-        $filter = @\stream_filter_append($fp, $filter, \STREAM_FILTER_WRITE, $parameters);
+        $filter = \stream_filter_append($fp, $filter, \STREAM_FILTER_WRITE, $parameters);
     }
 
+    \restore_error_handler();
+
     if ($filter === false) {
         \fclose($fp);
-        $error = \error_get_last() + array('message' => '');
-        throw new \RuntimeException('Unable to access built-in filter: ' . $error['message']);
+        throw new \RuntimeException('Unable to access built-in filter: ' . $errstr);
     }
 
     // append filter function which buffers internally
@@ -301,10 +338,26 @@ function fun($filter, $parameters = null)
  */
 function remove($filter)
 {
-    if (@\stream_filter_remove($filter) === false) {
+    $errstr = '';
+    \set_error_handler(function ($_, $error) use (&$errstr) {
+        // Match errstr from PHP's warning message.
+        // stream_filter_remove() expects parameter 1 to be resource,...
+        $errstr = $error;
+    });
+
+    try {
+        $ret = \stream_filter_remove($filter);
+    } catch (\TypeError $e) { // @codeCoverageIgnoreStart
+        // Throws TypeError on PHP 8.0+
+        \restore_error_handler();
+        throw $e;
+    } // @codeCoverageIgnoreEnd
+
+    \restore_error_handler();
+
+    if ($ret === false) {
         // PHP 8 throws above on type errors, older PHP and memory issues can throw here
-        $error = \error_get_last();
-        throw new \RuntimeException('Unable to remove filter: ' . $error['message']);
+        throw new \RuntimeException('Unable to remove filter: ' . $errstr);
     }
 }
 
diff --git a/tests/FilterTest.php b/tests/FilterTest.php
index 2b2d01d..f418588 100644
--- a/tests/FilterTest.php
+++ b/tests/FilterTest.php
@@ -335,31 +335,118 @@ public function testAppendThrowsShouldTriggerEndButIgnoreExceptionDuringEnd()
         $this->assertContainsString('test', $errors[0]);
     }
 
-    public function testAppendInvalidStreamIsRuntimeError()
+    public function testAppendThrowsForInvalidEncodingAndUnsetsUsedErrorHandler()
+    {
+        $handler = set_error_handler(function () { });
+
+        restore_error_handler();
+
+        try {
+            StreamFilter\append(false, function () { });
+        } catch (\TypeError $e) {
+            // handle Error to unset Error handler afterwards (PHP >= 8.0)
+        } catch (\RunTimeException $e) {
+            // handle Error to unset Error handler afterwards (PHP < 8.0)
+        }
+
+        $checkHandler = set_error_handler(function () { });
+        restore_error_handler();
+
+        $this->assertEquals($handler, $checkHandler);
+    }
+
+    public function testAppendInvalidStreamIsRuntimeErrorWithoutCallingCustomErrorHandler()
     {
         if (PHP_VERSION >= 8) $this->markTestSkipped('Not supported on PHP 8+ (PHP 8 throws TypeError automatically)');
 
         $this->setExpectedException('RuntimeException');
         if (defined('HHVM_VERSION')) $this->markTestSkipped('Not supported on HHVM (does not reject invalid stream)');
+
+        $error = null;
+        set_error_handler(function ($_, $errstr) use (&$error) {
+            $error = $errstr;
+        });
+
         StreamFilter\append(false, function () { });
+
+        restore_error_handler();
+        $this->assertNull($error);
     }
 
-    public function testPrependInvalidStreamIsRuntimeError()
+    public function testPrependThrowsForInvalidEncodingAndUnsetsUsedErrorHandler()
+    {
+        $handler = set_error_handler(function () { });
+
+        restore_error_handler();
+
+        try {
+            StreamFilter\prepend(false, function () { });
+        } catch (\TypeError $e) {
+            // handle Error to unset Error handler afterwards (PHP >= 8.0)
+        } catch (\RunTimeException $e) {
+            // handle Error to unset Error handler afterwards (PHP < 8.0)
+        }
+
+        $checkHandler = set_error_handler(function () { });
+        restore_error_handler();
+
+        $this->assertEquals($handler, $checkHandler);
+    }
+
+    public function testPrependInvalidStreamIsRuntimeErrorWithoutCallingCustomErrorHandler()
     {
         if (PHP_VERSION >= 8) $this->markTestSkipped('Not supported on PHP 8+ (PHP 8 throws TypeError automatically)');
 
         $this->setExpectedException('RuntimeException');
         if (defined('HHVM_VERSION')) $this->markTestSkipped('Not supported on HHVM (does not reject invalid stream)');
+
+        $error = null;
+        set_error_handler(function ($_, $errstr) use (&$error) {
+            $error = $errstr;
+        });
+
         StreamFilter\prepend(false, function () { });
+
+        restore_error_handler();
+        $this->assertNull($error);
+    }
+
+    public function testRemoveThrowsForInvalidEncodingAndUnsetsUsedErrorHandler()
+    {
+        $handler = set_error_handler(function () { });
+
+        restore_error_handler();
+
+        try {
+            StreamFilter\remove(false);
+        } catch (\TypeError $e) {
+            // handle Error to unset Error handler afterwards (PHP >= 8.0)
+        } catch (\RunTimeException $e) {
+            // handle Error to unset Error handler afterwards (PHP < 8.0)
+        }
+
+        $checkHandler = set_error_handler(function () { });
+        restore_error_handler();
+
+        $this->assertEquals($handler, $checkHandler);
     }
 
-    public function testRemoveInvalidFilterIsRuntimeError()
+    public function testRemoveInvalidFilterIsRuntimeErrorWithoutCallingCustomErrorHandler()
     {
         if (PHP_VERSION >= 8) $this->markTestSkipped('Not supported on PHP 8+ (PHP 8 throws TypeError automatically)');
 
         $this->setExpectedException('RuntimeException', 'Unable to remove filter: stream_filter_remove() expects parameter 1 to be resource, ');
         if (defined('HHVM_VERSION')) $this->markTestSkipped('Not supported on HHVM (does not reject invalid filters)');
+
+        $error = null;
+        set_error_handler(function ($_, $errstr) use (&$error) {
+            $error = $errstr;
+        });
+
         StreamFilter\remove(false);
+
+        restore_error_handler();
+        $this->assertNull($error);
     }
 
     /**
diff --git a/tests/FunTest.php b/tests/FunTest.php
index 5e03cbd..00a5e69 100644
--- a/tests/FunTest.php
+++ b/tests/FunTest.php
@@ -35,10 +35,19 @@ public function testFunWriteAfterCloseRot13()
         $rot('test');
     }
 
-    public function testFunInvalid()
+    public function testFunInvalidWithoutCallingCustomErrorHandler()
     {
         $this->setExpectedException('RuntimeException');
+
+        $error = null;
+        set_error_handler(function ($_, $errstr) use (&$error) {
+            $error = $errstr;
+        });
+
         Filter\fun('unknown');
+
+        restore_error_handler();
+        $this->assertNull($error);
     }
 
     public function testFunInBase64()