diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index 626bb20fb48..6ad0b6eb76f 100644
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -2406,6 +2406,10 @@ PHP_FUNCTION(preg_replace_callback_array)
 			zend_argument_type_error(1, "must contain only valid callbacks");
 			goto error;
 		}
+		if (!str_idx_regex) {
+			zend_argument_type_error(1, "must contain only string patterns as keys");
+			goto error;
+		}
 
 		ZVAL_COPY_VALUE(&fci.function_name, replace);
 
diff --git a/ext/pcre/tests/preg_replace_callback_array_numeric_index_error.phpt b/ext/pcre/tests/preg_replace_callback_array_numeric_index_error.phpt
new file mode 100644
index 00000000000..55dfabce864
--- /dev/null
+++ b/ext/pcre/tests/preg_replace_callback_array_numeric_index_error.phpt
@@ -0,0 +1,15 @@
+--TEST--
+preg_replace_callback_array() invalid pattern
+--FILE--
+<?php
+preg_replace_callback_array(
+    [42 => function () {}],
+    'a',
+);
+?>
+--EXPECTF--
+Fatal error: Uncaught TypeError: preg_replace_callback_array(): Argument #1 ($pattern) must contain only string patterns as keys in %s:%d
+Stack trace:
+#0 %s(%d): preg_replace_callback_array(Array, 'a')
+#1 {main}
+  thrown in %s on line %d