diff --git a/README b/README
index 10b88d15e0..2f0c41d4f4 100644
--- a/README
+++ b/README
@@ -472,6 +472,7 @@ Required by default:
   * libraw
   * libspectre
   * librsvg
+  * openmp (clang needs libomp, while gcc uses libgomp)
 
 You might want webp support so disable fewer loaders and remove webp
 from the disablers with: