diff --git a/docs/usermanual-clusters.xml b/docs/usermanual-clusters.xml
index 228cc560a..de7d219c3 100644
--- a/docs/usermanual-clusters.xml
+++ b/docs/usermanual-clusters.xml
@@ -492,7 +492,7 @@
     </para>
     <para>
       But this initial cluster-merging behavior makes it impossible
-      client programs to implement some features (such as to
+      for client programs to implement some features (such as to
       color diacritic marks differently from their base
       characters). That is why, in level 1, HarfBuzz does not perform
       the initial merging step.