diff --git a/src/wp-includes/class-wp-scripts.php b/src/wp-includes/class-wp-scripts.php
index e48658a1e7f7c..372cfc1fdc1ce 100644
--- a/src/wp-includes/class-wp-scripts.php
+++ b/src/wp-includes/class-wp-scripts.php
@@ -366,6 +366,8 @@ public function do_item( $handle, $group = false ) {
 			$translations  = wp_get_inline_script_tag( $translations, array( 'id' => "{$handle}-js-translations" ) );
 		}
 
+		$restore_concat_after_print = false;
+
 		if ( $this->do_concat ) {
 			/**
 			 * Filters the script loader source.
@@ -393,8 +395,27 @@ public function do_item( $handle, $group = false ) {
 				$this->concat_version .= "$handle$ver";
 				return true;
 			} else {
-				$this->ext_handles .= "$handle,";
-				$this->ext_version .= "$handle$ver";
+				$has_pending_dependents = false;
+
+				if ( $src ) {
+					foreach ( $this->get_dependents( $handle ) as $dependent ) {
+						if ( in_array( $dependent, $this->to_do, true ) && ! in_array( $dependent, $this->done, true ) ) {
+							$has_pending_dependents = true;
+							break;
+						}
+					}
+				}
+
+				if ( $has_pending_dependents ) {
+					$this->do_concat = false;
+
+					_print_scripts();
+					$this->reset();
+					$restore_concat_after_print = true;
+				} else {
+					$this->ext_handles .= "$handle,";
+					$this->ext_version .= "$handle$ver";
+				}
 			}
 		}
 
@@ -448,6 +469,9 @@ public function do_item( $handle, $group = false ) {
 		$src = esc_url_raw( apply_filters( 'script_loader_src', $src, $handle ) );
 
 		if ( ! $src ) {
+			if ( $restore_concat_after_print ) {
+				$this->do_concat = true;
+			}
 			return true;
 		}
 
@@ -501,6 +525,10 @@ public function do_item( $handle, $group = false ) {
 			echo $tag;
 		}
 
+		if ( $restore_concat_after_print ) {
+			$this->do_concat = true;
+		}
+
 		return true;
 	}
 
diff --git a/tests/phpunit/tests/dependencies/scripts.php b/tests/phpunit/tests/dependencies/scripts.php
index 41c9673915b93..cf32f9fcf2732 100644
--- a/tests/phpunit/tests/dependencies/scripts.php
+++ b/tests/phpunit/tests/dependencies/scripts.php
@@ -3756,6 +3756,35 @@ public function data_wp_localize_script_data_formats() {
 		);
 	}
 
+	/**
+	 * @ticket 15833
+	 *
+	 * @covers WP_Scripts::do_item
+	 */
+	public function test_concatenation_preserves_external_dependency_order() {
+		global $wp_scripts, $wp_version;
+
+		$wp_scripts->do_concat    = true;
+		$wp_scripts->default_dirs = array( '/default/' );
+
+		wp_enqueue_script( 'one', '/default/one.js', array(), null );
+		wp_enqueue_script( 'external', 'https://example.com/external.js', array( 'one' ), null );
+		wp_enqueue_script( 'three', '/default/three.js', array( 'external' ), null );
+
+		$print_scripts = get_echo(
+			static function () {
+				wp_print_scripts();
+				_print_scripts();
+			}
+		);
+
+		$expected  = "<script src='/wp-admin/load-scripts.php?c=0&amp;load%5Bchunk_0%5D=one&amp;ver={$wp_version}'></script>\n";
+		$expected .= "<script src='https://example.com/external.js' id='external-js'></script>\n";
+		$expected .= "<script src='/wp-admin/load-scripts.php?c=0&amp;load%5Bchunk_0%5D=three&amp;ver={$wp_version}'></script>\n";
+
+		$this->assertEqualHTML( $expected, $print_scripts );
+	}
+
 	/**
 	 * @ticket 55628
 	 *