diff --git a/xpcom/idl-parser/header.py b/xpcom/idl-parser/header.py
index b2a7bdc93a2..0e4e767a20f 100644
--- a/xpcom/idl-parser/header.py
+++ b/xpcom/idl-parser/header.py
@@ -351,7 +351,7 @@ def write_interface(iface, fd):
     def write_attr_decl(a):
         printComments(fd, a.doccomments, '  ')
 
-        fd.write("  /* %s */\n" % a.toIDL());
+        fd.write("  /* %s */\n" % a.toIDL())
 
         fd.write("  %s = 0;\n" % attributeAsNative(a, True))
         if a.infallible:
diff --git a/xpcom/idl-parser/xpidl.py b/xpcom/idl-parser/xpidl.py
index 07b566ac809..4ef577b5442 100755
--- a/xpcom/idl-parser/xpidl.py
+++ b/xpcom/idl-parser/xpidl.py
@@ -740,20 +740,20 @@ class Attribute(object):
                     raise IDLError("'Null' attribute requires a value", aloc)
                 if readonly:
                     raise IDLError("'Null' attribute only makes sense for setters",
-                                   aloc);
+                                   aloc)
                 if value not in ('Empty', 'Null', 'Stringify'):
                     raise IDLError("'Null' attribute value must be 'Empty', 'Null' or 'Stringify'",
-                                   aloc);
+                                   aloc)
                 self.null = value
             elif name == 'Undefined':
                 if value is None:
                     raise IDLError("'Undefined' attribute requires a value", aloc)
                 if readonly:
                     raise IDLError("'Undefined' attribute only makes sense for setters",
-                                   aloc);
+                                   aloc)
                 if value not in ('Empty', 'Null'):
                     raise IDLError("'Undefined' attribute value must be 'Empty' or 'Null'",
-                                   aloc);
+                                   aloc)
                 self.undefined = value
             else:
                 if value is not None:
@@ -949,14 +949,14 @@ class Param(object):
                     raise IDLError("'Null' must specify a parameter", aloc)
                 if value not in ('Empty', 'Null', 'Stringify'):
                     raise IDLError("'Null' parameter value must be 'Empty', 'Null', or 'Stringify'",
-                                   aloc);
+                                   aloc)
                 self.null = value
             elif name == 'Undefined':
                 if value is None:
                     raise IDLError("'Undefined' must specify a parameter", aloc)
                 if value not in ('Empty', 'Null'):
                     raise IDLError("'Undefined' parameter value must be 'Empty' or 'Null'",
-                                   aloc);
+                                   aloc)
                 self.undefined = value
             else:
                 if value is not None: