diff --git a/ext/soap/php_http.c b/ext/soap/php_http.c
index c1dd29e828e..2f4ee5150ca 100644
--- a/ext/soap/php_http.c
+++ b/ext/soap/php_http.c
@@ -861,7 +861,9 @@ try_again:
 		smart_str_0(&soap_headers);
 		if (Z_TYPE_P(Z_CLIENT_TRACE_P(this_ptr)) == IS_TRUE) {
 			zval_ptr_dtor(Z_CLIENT_LAST_REQUEST_HEADERS_P(this_ptr));
-			ZVAL_STR_COPY(Z_CLIENT_LAST_REQUEST_HEADERS_P(this_ptr), soap_headers.s);
+			/* Need to copy the string here, as we continue appending to soap_headers below. */
+			ZVAL_STRINGL(Z_CLIENT_LAST_REQUEST_HEADERS_P(this_ptr),
+				ZSTR_VAL(soap_headers.s), ZSTR_LEN(soap_headers.s));
 		}
 		smart_str_appendl(&soap_headers, request->val, request->len);
 		smart_str_0(&soap_headers);
diff --git a/ext/soap/tests/bug73452.phpt b/ext/soap/tests/bug73452.phpt
index 3383ee2994a..d818ba15f49 100644
--- a/ext/soap/tests/bug73452.phpt
+++ b/ext/soap/tests/bug73452.phpt
@@ -11,7 +11,7 @@ echo unserialize($data);
 ?>
 ==DONE==
 --EXPECTF--
-Fatal error: Uncaught TypeError: Cannot assign int to property SoapFault::$faultcode of type ?string in %s:%d
+Fatal error: Uncaught TypeError: Cannot assign %s to property SoapFault::$faultcode of type ?string in %s:%d
 Stack trace:
 #0 %sbug73452.php(4): unserialize('O:9:"SoapFault"...')
 #1 {main}