diff --git a/lib/repl_type_completor/type_analyzer.rb b/lib/repl_type_completor/type_analyzer.rb
index 0e70b32..ffeb338 100644
--- a/lib/repl_type_completor/type_analyzer.rb
+++ b/lib/repl_type_completor/type_analyzer.rb
@@ -261,7 +261,9 @@ def evaluate_call_node(node, scope)
               when Prism::NumberedParametersNode
                 assign_numbered_parameters node.block.parameters.maximum, block_scope, block_args, {}
               when Prism::BlockParametersNode
-                assign_parameters node.block.parameters.parameters, block_scope, block_args, {}
+                if node.block.parameters.parameters
+                  assign_parameters node.block.parameters.parameters, block_scope, block_args, {}
+                end
               end
               result = node.block.body ? evaluate(node.block.body, block_scope) : Types::NIL
               block_scope.merge_jumps
diff --git a/test/repl_type_completor/test_type_analyze.rb b/test/repl_type_completor/test_type_analyze.rb
index a8f9a58..33004e9 100644
--- a/test/repl_type_completor/test_type_analyze.rb
+++ b/test/repl_type_completor/test_type_analyze.rb
@@ -680,6 +680,7 @@ def test_call_parameter
     end
 
     def test_block_args
+      assert_call('[1,2,3].tap{|| 1.', include: Integer)
       assert_call('[1,2,3].tap{|a| a.', include: Array)
       assert_call('[1,2,3].tap{|a,| a.', include: Integer)
       assert_call('[1,2,3].tap{|a,b| a.', include: Integer)