diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index 2c1e029d3cd..ead02cbbc79 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -1144,6 +1144,7 @@ static type_t *make_type(unsigned char type, type_t *ref)
   t->sign = 0;
   t->defined = FALSE;
   t->written = FALSE;
+  t->user_types_registered = FALSE;
   t->typelib_idx = -1;
   INIT_LINK(t);
   return t;
@@ -1203,6 +1204,7 @@ static var_t *make_var(char *name)
   v->name = name;
   v->ptr_level = 0;
   v->type = NULL;
+  v->args = NULL;
   v->tname = NULL;
   v->attrs = NULL;
   v->array = NULL;
diff --git a/tools/widl/typelib.c b/tools/widl/typelib.c
index 7a1b246d8ce..52180705858 100644
--- a/tools/widl/typelib.c
+++ b/tools/widl/typelib.c
@@ -220,6 +220,8 @@ void start_typelib(char *name, attr_t *attrs)
     typelib->name = xstrdup(name);
     typelib->filename = xstrdup(typelib_name);
     typelib->attrs = attrs;
+    typelib->entry = NULL;
+    typelib->importlibs = NULL;
 }
 
 void end_typelib(void)
@@ -373,6 +375,7 @@ static void read_msft_importlib(importlib_t *importlib, int fd)
             importlib->importinfos[i].flags |= MSFT_IMPINFO_OFFSET_IS_GUID;
             msft_read_guid(fd, &segdir, base.posguid, &importlib->importinfos[i].guid);
         }
+        else memset( &importlib->importinfos[i].guid, 0, sizeof(importlib->importinfos[i].guid));
 
         tlb_lseek(fd, segdir.pNametab.offset + base.NameOffset);
         tlb_read(fd, &nameintro, sizeof(nameintro));
@@ -431,6 +434,7 @@ void add_importlib(const char *name)
     chat("add_importlib: %s\n", name);
 
     importlib = xmalloc(sizeof(*importlib));
+    memset( importlib, 0, sizeof(*importlib) );
     importlib->name = xstrdup(name);
 
     read_importlib(importlib);
diff --git a/tools/widl/utils.c b/tools/widl/utils.c
index 9f82184cd94..fea0540bc61 100644
--- a/tools/widl/utils.c
+++ b/tools/widl/utils.c
@@ -145,7 +145,7 @@ char *dup_basename(const char *name, const char *ext)
 	namelen = strlen(name);
 
 	/* +4 for later extension and +1 for '\0' */
-	base = (char *)xmalloc(namelen +4 +1);
+	base = xmalloc(namelen +4 +1);
 	strcpy(base, name);
 	if(!strcasecmp(name + namelen-extlen, ext))
 	{
@@ -164,12 +164,7 @@ void *xmalloc(size_t size)
     {
 	error("Virtual memory exhausted.\n");
     }
-    /*
-     * We set it to 0.
-     * This is *paramount* because we depend on it
-     * just about everywhere in the rest of the code.
-     */
-    memset(res, 0, size);
+    memset(res, 0x55, size);
     return res;
 }
 
@@ -192,6 +187,6 @@ char *xstrdup(const char *str)
 	char *s;
 
 	assert(str != NULL);
-	s = (char *)xmalloc(strlen(str)+1);
+	s = xmalloc(strlen(str)+1);
 	return strcpy(s, str);
 }
diff --git a/tools/widl/widltypes.h b/tools/widl/widltypes.h
index cf0f2462a34..eeaa627200f 100644
--- a/tools/widl/widltypes.h
+++ b/tools/widl/widltypes.h
@@ -49,7 +49,7 @@ typedef struct _typelib_t typelib_t;
   type *l_next; \
   type *l_prev
 
-#define LINK(x,y) do { x->l_next = y; if (y) y->l_prev = x; } while (0)
+#define LINK(x,y) do { x->l_next = y; x->l_prev = NULL; if (y) y->l_prev = x; } while (0)
 
 #define INIT_LINK(x) do { x->l_next = NULL; x->l_prev = NULL; } while (0)
 #define NEXT_LINK(x) ((x)->l_next)
diff --git a/tools/widl/write_msft.c b/tools/widl/write_msft.c
index cac1f7f9f2d..23074936c8b 100644
--- a/tools/widl/write_msft.c
+++ b/tools/widl/write_msft.c
@@ -1734,6 +1734,7 @@ static msft_typeinfo_t *create_msft_typeinfo(msft_typelib_t *typelib, enum type_
     chat("create_msft_typeinfo: name %s kind %d\n", name, kind);
 
     msft_typeinfo = xmalloc(sizeof(*msft_typeinfo));
+    memset( msft_typeinfo, 0, sizeof(*msft_typeinfo) );
 
     msft_typeinfo->typelib = typelib;