diff --git a/ext/spl/tests/bug78042.phpt b/ext/spl/tests/bug78042.phpt
new file mode 100644
index 0000000000000..2cdd89ef6dcca
--- /dev/null
+++ b/ext/spl/tests/bug78042.phpt
@@ -0,0 +1,26 @@
+--TEST--
+Bug #78042 (SplTempFileObject::isReadable() / SplTempFileObject::isWritable() return values)
+--FILE--
+<?php
+$file = new \SplTempFileObject(-1);
+$written = $file->fwrite('readable content');
+$file->fflush();
+$file->rewind();
+var_dump($file->getFileInfo()->getPathname());
+var_dump($file->valid());
+var_dump($file->isReadable());
+var_dump($file->fread($written));
+var_dump($file->isWritable());
+$written += $file->fwrite(' is writable');
+$file->fflush();
+$file->rewind();
+var_dump($file->fread($written));
+
+?>
+--EXPECT--
+string(12) "php://memory"
+bool(true)
+bool(true)
+string(16) "readable content"
+bool(true)
+string(28) "readable content is writable"