diff --git a/wp-includes/load.php b/wp-includes/load.php
index e2b388fb77..3551daf6da 100644
--- a/wp-includes/load.php
+++ b/wp-includes/load.php
@@ -333,7 +333,7 @@ function wp_debug_mode() {
 		error_reporting( E_CORE_ERROR | E_CORE_WARNING | E_COMPILE_ERROR | E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR );
 	}
 
-	if ( defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) || wp_doing_ajax() ) {
+	if ( defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) || wp_doing_ajax() || wp_is_json_request() ) {
 		@ini_set( 'display_errors', 0 );
 	}
 }
@@ -1162,3 +1162,24 @@ function wp_finalize_scraping_edited_file_errors( $scrape_key ) {
 	}
 	echo "\n###### wp_scraping_result_end:$scrape_key ######\n";
 }
+
+/**
+ * Checks whether current request is a JSON request, or is expecting a JSON response.
+ *
+ * @since 5.0.0
+ *
+ * @return bool True if Accepts or Content-Type headers contain application/json, false otherwise.
+ */
+function wp_is_json_request() {
+
+	if ( isset( $_SERVER['HTTP_ACCEPT'] ) && false !== strpos( $_SERVER['HTTP_ACCEPT'], 'application/json' ) ) {
+		return true;
+	}
+
+	if ( isset( $_SERVER['CONTENT_TYPE'] ) && 'application/json' === $_SERVER['CONTENT_TYPE'] ) {
+		return true;
+	}
+
+	return false;
+
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 29623edd09..a9d95e710d 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43729';
+$wp_version = '5.0-alpha-43730';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.