diff --git a/lib/solargraph/pin/base.rb b/lib/solargraph/pin/base.rb
index e6a630562..c626101f2 100644
--- a/lib/solargraph/pin/base.rb
+++ b/lib/solargraph/pin/base.rb
@@ -144,7 +144,7 @@ def choose_longer(other, attr)
       def combine_directives(other)
         return self.directives if other.directives.empty?
         return other.directives if directives.empty?
-        [directives + other.directives].uniq
+        (directives + other.directives).uniq
       end
 
       # @param other [self]