diff --git a/chibicc.h b/chibicc.h
index 509d595b39c7f1e3aed77d0516b291a93fb7d0a8..30a26fd7f11eb2fc654ee1b5754ef1a758c3be7c 100644
--- a/chibicc.h
+++ b/chibicc.h
@@ -164,6 +164,7 @@ Program *program();
 //
 
 typedef enum {
+  TY_VOID,
   TY_CHAR,
   TY_SHORT,
   TY_INT,
@@ -192,6 +193,7 @@ struct Member {
 };
 
 int align_to(int n, int align);
+Type *void_type();
 Type *char_type();
 Type *short_type();
 Type *int_type();
diff --git a/parse.c b/parse.c
index 7557efddf1e0a4db26c1ecf28aaa2ccfc3ffbb93..03e8eebe1cdc900a5ff3f5bba109554f4ea4b9c2 100644
--- a/parse.c
+++ b/parse.c
@@ -170,11 +170,13 @@ Program *program() {
 }
 
 // type-specifier = builtin-type | struct-decl | typedef-name
-// builtin-type   = "char" | "short" | "int" | "long"
+// builtin-type   = "void" | "char" | "short" | "int" | "long"
 Type *type_specifier() {
   if (!is_typename(token))
     error_tok(token, "typename expected");
 
+  if (consume("void"))
+    return void_type();
   if (consume("char"))
     return char_type();
   if (consume("short"))
@@ -364,8 +366,11 @@ Node *declaration() {
   char *name = NULL;
   ty = declarator(ty, &name);
   ty = type_suffix(ty);
-  Var *var = push_var(name, ty, true);
 
+  if (ty->kind == TY_VOID)
+    error_tok(tok, "variable declared void");
+
+  Var *var = push_var(name, ty, true);
   if (consume(";"))
     return new_node(ND_NULL, tok);
 
@@ -383,8 +388,8 @@ Node *read_expr_stmt() {
 }
 
 bool is_typename() {
-  return peek("char") || peek("short") || peek("int") || peek("long") ||
-         peek("struct") || find_typedef(token);
+  return peek("void") || peek("char") || peek("short") || peek("int") ||
+         peek("long") || peek("struct") || find_typedef(token);
 }
 
 // stmt = "return" expr ";"
diff --git a/tests b/tests
index 6aec64fa39793e2cec95206b4462c88495facf8f..bb0073a7922739ebf85e38cd1ddec37c4bf0dcaf 100644
--- a/tests
+++ b/tests
@@ -273,6 +273,8 @@ int main() {
 
   assert(3, *g1_ptr(), "*g1_ptr()");
 
+  { void *x; }
+
   printf("OK\n");
   return 0;
 }
diff --git a/tokenize.c b/tokenize.c
index 3eae8c50d1435b32faf42eea5a2c0c123d35c6ad..8acdfdfa901478b40b618f682c77bdb06fe967ad 100644
--- a/tokenize.c
+++ b/tokenize.c
@@ -153,7 +153,7 @@ char *starts_with_reserved(char *p) {
   // Keyword
   static char *kw[] = {"return", "if", "else", "while", "for", "int",
                        "char", "sizeof", "struct", "typedef", "short",
-                       "long"};
+                       "long", "void"};
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) {
     int len = strlen(kw[i]);
diff --git a/type.c b/type.c
index 5c6bb8b237ebf1cd434f31cc8b5a665595fe2b63..403cfbc1722e7f85cd1a2750a221623f05f6d4ba 100644
--- a/type.c
+++ b/type.c
@@ -11,6 +11,10 @@ Type *new_type(TypeKind kind, int align) {
   return ty;
 }
 
+Type *void_type() {
+  return new_type(TY_VOID, 1);
+}
+
 Type *char_type() {
   return new_type(TY_CHAR, 1);
 }
@@ -47,6 +51,8 @@ Type *array_of(Type *base, int size) {
 }
 
 int size_of(Type *ty) {
+  assert(ty->kind != TY_VOID);
+
   switch (ty->kind) {
   case TY_CHAR:
     return 1;
@@ -144,6 +150,8 @@ void visit(Node *node) {
     if (!node->lhs->ty->base)
       error_tok(node->tok, "invalid pointer dereference");
     node->ty = node->lhs->ty->base;
+    if (node->ty->kind == TY_VOID)
+      error_tok(node->tok, "dereferencing a void pointer");
     return;
   case ND_SIZEOF:
     node->kind = ND_NUM;