diff --git a/Zend/tests/bug73987.phpt b/Zend/tests/bug73987.phpt
index 551565650c8..610b594a644 100644
--- a/Zend/tests/bug73987.phpt
+++ b/Zend/tests/bug73987.phpt
@@ -1,5 +1,5 @@
 --TEST--
-Bug #73987 (Method compatibility check looks to original definition and not parent)
+Bug #73987 (Method compatibility check looks to original definition and not parent - nullability interface)
 --FILE--
 <?php
 
diff --git a/Zend/tests/bug73987_1.phpt b/Zend/tests/bug73987_1.phpt
index 6a0a157f29a..010987ea5f6 100644
--- a/Zend/tests/bug73987_1.phpt
+++ b/Zend/tests/bug73987_1.phpt
@@ -1,5 +1,5 @@
 --TEST--
-Bug #73987 (Method compatibility check looks to original definition and not parent)
+Bug #73987 (Method compatibility check looks to original definition and not parent - return types interface)
 --FILE--
 <?php
 
diff --git a/Zend/tests/bug73987_2.phpt b/Zend/tests/bug73987_2.phpt
new file mode 100644
index 00000000000..a70f1455e89
--- /dev/null
+++ b/Zend/tests/bug73987_2.phpt
@@ -0,0 +1,20 @@
+--TEST--
+Bug #73987 (Method compatibility check looks to original definition and not parent - nullabilty abstract)
+--FILE--
+<?php
+
+abstract class A {
+    abstract function example($a, $b, $c);
+}
+
+class B extends A {
+    function example($a, $b = null, $c = null) { }
+}
+
+class C extends B {
+    function example($a, $b, $c = null) { }
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of C::example($a, $b, $c = NULL) must be compatible with B::example($a, $b = NULL, $c = NULL) in %s
diff --git a/Zend/tests/bug73987_3.phpt b/Zend/tests/bug73987_3.phpt
new file mode 100644
index 00000000000..89e4686ed6f
--- /dev/null
+++ b/Zend/tests/bug73987_3.phpt
@@ -0,0 +1,20 @@
+--TEST--
+Bug #73987 (Method compatibility check looks to original definition and not parent - return types abstract)
+--FILE--
+<?php
+
+abstract class A {
+    abstract function example();
+}
+
+class B extends A {
+    function example(): int  { }
+}
+
+class C extends B {
+    function example(): string { }
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of C::example(): string must be compatible with B::example(): int in %s