diff --git a/cgen/__init__.py b/cgen/__init__.py
index 7d9a8b1..9a0572d 100644
--- a/cgen/__init__.py
+++ b/cgen/__init__.py
@@ -748,7 +748,7 @@ def make_multiple_ifs(conditions_and_blocks, base=None):
 # {{{ simple statements
 
 class Define(Generable):
-    def __init__(self, symbol, value):
+    def __init__(self, symbol, value=""):
         self.symbol = symbol
         self.value = value
 
@@ -1060,12 +1060,15 @@ class IfDef(Module):
     :param iflines: the block of code inside the if [an array of type Generable]
     :param elselines: the block of code inside the else [an array of type Generable]
     """
-    def __init__(self, condition, iflines, elselines):
+    def __init__(self, condition, iflines, elselines=None):
         ifdef_line = Line('#ifdef %s' % condition)
-        if len(elselines):
-            elselines.insert(0, Line('#else'))
-        endif_line = Line('#endif')
-        lines = [ifdef_line]+iflines+elselines+[endif_line]
+        lines = [ifdef_line] + iflines
+
+        if elselines:
+            lines += [Line('#else')]
+            lines += elselines
+
+        lines += [Line('#endif')]
         super(IfDef, self).__init__(lines)
 
     mapper_method = "map_ifdef"
@@ -1079,11 +1082,15 @@ class IfNDef(Module):
         [an array of type Generable]
     :param elselines: the block of code inside the else [an array of type Generable]
     """
-    def __init__(self, condition, ifndeflines, elselines):
+    def __init__(self, condition, ifndeflines, elselines=None):
         ifndefdef_line = Line('#ifndef %s' % condition)
-        if len(elselines):
-            elselines.insert(0, Line('#else'))
-        lines = [ifndefdef_line]+ifndeflines+elselines+[Line('#endif')]
+        lines = [ifndefdef_line] + ifndeflines
+
+        if elselines:
+            lines += [Line('#else')]
+            lines += elselines
+
+        lines += [Line('#endif')]
         super(IfNDef, self).__init__(lines)
 
     mapper_method = "map_ifndef"
diff --git a/test/test_cgen.py b/test/test_cgen.py
index b1de365..ce1e636 100644
--- a/test/test_cgen.py
+++ b/test/test_cgen.py
@@ -1,7 +1,8 @@
+import sys
 from cgen import (
         POD, Struct, FunctionBody, FunctionDeclaration,
         For, If, Assign, Value, Block, ArrayOf, Comment,
-        Template)
+        Template, Pointer, IfNDef, IfDef, Define)
 import numpy as np
 
 
@@ -46,3 +47,68 @@ def test_cgen():
     print(s)
     print(f_body)
     print(t_decl)
+
+
+def test_ptr_to_array():
+    t2 = Pointer(Pointer(ArrayOf(POD(np.float32, "yyy"), 2)))
+    assert str(t2) == "float **yyy[2];"
+
+
+def test_ifndef_no_else():
+    expected = """#ifndef SOME_DEFINE
+/* TRUE */
+#endif"""
+
+    code = IfNDef("SOME_DEFINE", [Comment("TRUE")])
+    assert str(code) == expected
+
+
+def test_ifndef():
+    expected = """#ifndef SOME_DEFINE
+/* TRUE */
+#else
+/* FALSE */
+#endif"""
+
+    code = IfNDef("SOME_DEFINE", [Comment("TRUE")], [Comment("FALSE")])
+    assert str(code) == expected
+
+
+def test_ifdef_no_else():
+    expected = """#ifdef SOME_DEFINE
+/* TRUE */
+#endif"""
+
+    code = IfDef("SOME_DEFINE", [Comment("TRUE")])
+    assert str(code) == expected
+
+
+def test_ifdef():
+    expected = """#ifdef SOME_DEFINE
+/* TRUE */
+#else
+/* FALSE */
+#endif"""
+
+    code = IfDef("SOME_DEFINE", [Comment("TRUE")], [Comment("FALSE")])
+    assert str(code) == expected
+
+
+def test_define_no_val():
+    expected = "#define SOME_DEFINE"
+    code = Define("SOME_DEFINE")
+    assert str(code) == expected
+
+
+def test_define_with_val():
+    expected = "#define SOME_DEFINE 42"
+    code = Define("SOME_DEFINE", 42)
+    assert str(code) == expected
+
+
+if __name__ == "__main__":
+    if len(sys.argv) > 1:
+        exec(sys.argv[1])
+    else:
+        from pytest import main
+        main([__file__])