diff --git a/src/prism.c b/src/prism.c
index 2946880424..950fbf7bef 100644
--- a/src/prism.c
+++ b/src/prism.c
@@ -12991,7 +12991,7 @@ pm_binding_powers_t pm_binding_powers[PM_TOKEN_MAXIMUM] = {
     [PM_TOKEN_PERCENT] = LEFT_ASSOCIATIVE(PM_BINDING_POWER_FACTOR),
     [PM_TOKEN_SLASH] = LEFT_ASSOCIATIVE(PM_BINDING_POWER_FACTOR),
     [PM_TOKEN_STAR] = LEFT_ASSOCIATIVE(PM_BINDING_POWER_FACTOR),
-    [PM_TOKEN_USTAR] = LEFT_ASSOCIATIVE(PM_BINDING_POWER_FACTOR),
+    [PM_TOKEN_USTAR] = RIGHT_ASSOCIATIVE_UNARY(PM_BINDING_POWER_FACTOR),
 
     // -@
     [PM_TOKEN_UMINUS] = RIGHT_ASSOCIATIVE_UNARY(PM_BINDING_POWER_UMINUS),