diff --git a/test/fiddle/test_closure.rb b/test/fiddle/test_closure.rb
index e9dcecef67..56839e7b63 100644
--- a/test/fiddle/test_closure.rb
+++ b/test/fiddle/test_closure.rb
@@ -6,15 +6,15 @@ end
 module Fiddle
   class TestClosure < Fiddle::TestCase
     def test_argument_errors
-      assert_raise(TypeError) do
+      assert_raises(TypeError) do
         Closure.new(TYPE_INT, TYPE_INT)
       end
 
-      assert_raise(TypeError) do
+      assert_raises(TypeError) do
         Closure.new('foo', [TYPE_INT])
       end
 
-      assert_raise(TypeError) do
+      assert_raises(TypeError) do
         Closure.new(TYPE_INT, ['meow!'])
       end
     end
diff --git a/test/fiddle/test_cparser.rb b/test/fiddle/test_cparser.rb
index 2810e393b2..4d4799d8d6 100644
--- a/test/fiddle/test_cparser.rb
+++ b/test/fiddle/test_cparser.rb
@@ -60,7 +60,7 @@ module Fiddle
     end
 
     def test_undefined_ctype
-      assert_raise(DLError) { parse_ctype('DWORD') }
+      assert_raises(DLError) { parse_ctype('DWORD') }
     end
 
     def test_undefined_ctype_with_type_alias
@@ -92,7 +92,7 @@ module Fiddle
     end
 
     def test_struct_undefined
-      assert_raise(DLError) { parse_struct_signature(['int i', 'DWORD cb']) }
+      assert_raises(DLError) { parse_struct_signature(['int i', 'DWORD cb']) }
     end
 
     def test_struct_undefined_with_type_alias
diff --git a/test/fiddle/test_func.rb b/test/fiddle/test_func.rb
index 01ac09b52c..529aaa8baf 100644
--- a/test/fiddle/test_func.rb
+++ b/test/fiddle/test_func.rb
@@ -12,7 +12,7 @@ module Fiddle
 
     def test_syscall_with_tainted_string
       f = Function.new(@libc['system'], [TYPE_VOIDP], TYPE_INT)
-      assert_raise(SecurityError) do
+      assert_raises(SecurityError) do
         Thread.new {
           $SAFE = 1
           f.call("uname -rs".taint)
diff --git a/test/fiddle/test_import.rb b/test/fiddle/test_import.rb
index f94d67b459..c83f50fe44 100644
--- a/test/fiddle/test_import.rb
+++ b/test/fiddle/test_import.rb
@@ -44,7 +44,7 @@ module Fiddle
 
   class TestImport < TestCase
     def test_ensure_call_dlload
-      err = assert_raise(RuntimeError) do
+      err = assert_raises(RuntimeError) do
         Class.new do
           extend Importer
           extern "void *strcpy(char*, char*)"