diff --git a/Zend/tests/bug69537.phpt b/Zend/tests/bug69537.phpt
new file mode 100644
index 00000000000..3151c350815
--- /dev/null
+++ b/Zend/tests/bug69537.phpt
@@ -0,0 +1,19 @@
+--TEST--
+Bug #69537 (__debugInfo with empty string for key gives error)
+--FILE--
+<?php
+class Foo {
+
+    public function __debugInfo(){
+        return ['' => 1];
+    }
+}
+
+var_dump(new Foo);
+?>
+--EXPECTF--
+object(Foo)#%d (%d) {
+  [""]=>
+  int(1)
+}
+
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 1401a6e051a..5f3114d10e1 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -1314,7 +1314,7 @@ ZEND_API int zend_unmangle_property_name_ex(const zend_string *name, const char
 
 	*class_name = NULL;
 
-	if (ZSTR_VAL(name)[0] != '\0') {
+	if (!ZSTR_LEN(name) || ZSTR_VAL(name)[0] != '\0') {
 		*prop_name = ZSTR_VAL(name);
 		if (prop_len) {
 			*prop_len = ZSTR_LEN(name);