diff --git a/lib/riot/context_helpers.rb b/lib/riot/context_helpers.rb
index 434ceb9..bec4c0f 100644
--- a/lib/riot/context_helpers.rb
+++ b/lib/riot/context_helpers.rb
@@ -183,7 +183,7 @@ def new_assertion(scope, *args, &definition)
       options = args.extract_options!
       definition ||= proc { topic.send(*args) }
       description = "#{scope} #{args.first}"
-      description << " with arguments(s): #{args.drop(1)}" if args.size > 1
+      description << " with arguments(s): #{args.slice(1, args.length)}" if args.size > 1
       (@assertions << assertion_class.new(description, options[:negative], &definition)).last
     end
 
diff --git a/test/core/context/deny_test.rb b/test/core/context/deny_test.rb
index 0a20954..150245a 100644
--- a/test/core/context/deny_test.rb
+++ b/test/core/context/deny_test.rb
@@ -2,48 +2,52 @@
 
 context "Using denies" do
 
-  helper(:denial_context) do |&assertion_block|
+  helper(:denial_context) do |actual|
     report = Riot::Context.new("Apple Jackie") do
-      denies("with false", &assertion_block)
+      denies("with false") { actual }
     end.run(MockReporter.new)
 
     [report.passes, report.failures, report.errors]
   end # denial_context
 
   asserts("result when returning false from the assertion block") do
-    denial_context { false }
+    denial_context(false)
   end.equals([1,0,0])
 
   asserts("result when returning true from the assertion block") do
-    denial_context { true }
+    denial_context(true)
   end.equals([0,1,0])
 
   asserts("result when assertion block has an exception") do
-    denial_context { raise Exception }
-  end.equals([0,0,1])
+    Riot::Context.new("Apple Jackie") do
+      denies("with false") { raise Exception }
+    end.run(MockReporter.new).errors
+  end.equals(1)
 
 end # Using denies
 
 context "Using should_not" do
 
-  helper(:denial_context) do |&assertion_block|
+  helper(:denial_context) do |actual|
     report = Riot::Context.new("Apple Jackie") do
-      should_not("with false", &assertion_block)
+      should_not("with false") { actual }
     end.run(MockReporter.new)
 
     [report.passes, report.failures, report.errors]
   end # denial_context
 
   asserts("result when returning false from the assertion block") do
-    denial_context { false }
+    denial_context(false)
   end.equals([1,0,0])
 
   asserts("result when returning true from the assertion block") do
-    denial_context { true }
+    denial_context(true)
   end.equals([0,1,0])
 
   asserts("result when assertion block has an exception") do
-    denial_context { raise Exception }
-  end.equals([0,0,1])
+    Riot::Context.new("Apple Jackie") do
+      should_not("with false") { raise Exception }
+    end.run(MockReporter.new).errors
+  end.equals(1)
 
 end # Using should_not
diff --git a/test/core/runnable/negative_assertion_test.rb b/test/core/runnable/negative_assertion_test.rb
index 7d76ec6..1d26d81 100644
--- a/test/core/runnable/negative_assertion_test.rb
+++ b/test/core/runnable/negative_assertion_test.rb
@@ -2,35 +2,35 @@
 
 context "A negative assertion test" do
 
-  helper(:negative_assertion) do |&definition|
-    Riot::Assertion.new("foo", true, &definition)
+  helper(:negative_assertion) do |definition|
+    Riot::Assertion.new("foo", true) { definition }
   end
 
   asserts("response when evaluated with false result") do
-    negative_assertion { false }.run(Riot::Situation.new)
+    negative_assertion(false).run(Riot::Situation.new)
   end.equals([:pass, ""])
   
   asserts("response when evaluated with nil result") do
-    negative_assertion { false }.run(Riot::Situation.new)
+    negative_assertion(false).run(Riot::Situation.new)
   end.equals([:pass, ""])
   
   asserts("response when evaluated with true result") do
-    negative_assertion { true }.run(Riot::Situation.new)
+    negative_assertion(true).run(Riot::Situation.new)
   end.equals([:fail, "Expected non-true but got true instead", nil, nil])
 
   asserts("response when evaluated with \"bar\" result") do
-    negative_assertion { "bar" }.run(Riot::Situation.new)
+    negative_assertion("bar").run(Riot::Situation.new)
   end.equals([:fail, "Expected non-true but got \"bar\" instead", nil, nil])
 
   asserts("response when evaluated with 0 result") do
-    negative_assertion { 0 }.run(Riot::Situation.new)
+    negative_assertion(0).run(Riot::Situation.new)
   end.equals([:fail, "Expected non-true but got 0 instead", nil, nil])
 
   helper(:big_exception) { @exception ||= Exception.new("blah") }
 
   asserts("response when evaluation errors") do
     exception = big_exception # :\
-    negative_assertion { raise exception }.run(Riot::Situation.new)
+    Riot::Assertion.new("foo", true) { raise exception }.run(Riot::Situation.new)
   end.equals { [:error, big_exception] }
 
 end # A negative assertion test