diff --git a/tools/binpac/src/pac_exttype.cc b/tools/binpac/src/pac_exttype.cc
index 659d4cdc5e..65c89245f9 100644
--- a/tools/binpac/src/pac_exttype.cc
+++ b/tools/binpac/src/pac_exttype.cc
@@ -1,6 +1,7 @@
 #include "pac_exttype.h"
 #include "pac_id.h"
 #include "pac_decl.h"
+#include "pac_output.h"
 
 bool ExternType::DefineValueVar() const
 	{
@@ -40,6 +41,13 @@ string ExternType::EvalMember(const ID *member_id) const
 		member_id->Name());
 	}
 
+void ExternType::GenInitCode(Output* out_cc, Env* env)
+	{
+	if ( IsNumericType() || IsPointerType() )
+		out_cc->println("%s = 0;", env->LValue(value_var()));
+	Type::GenInitCode(out_cc, env);
+	}
+
 void ExternType::DoGenParseCode(Output* out, Env* env, const DataPtr& data, int flags)
 	{
 	ASSERT(0);
diff --git a/tools/binpac/src/pac_exttype.h b/tools/binpac/src/pac_exttype.h
index 6d81608195..a15ff6342e 100644
--- a/tools/binpac/src/pac_exttype.h
+++ b/tools/binpac/src/pac_exttype.h
@@ -26,6 +26,8 @@ public:
 	bool IsNumericType() const		{ return ext_type_ == NUMBER; }
 	bool IsPointerType() const		{ return ext_type_ == POINTER; }
 
+	void GenInitCode(Output *out_cc, Env *env);
+
 protected:
 	void DoGenParseCode(Output *out, Env *env, const DataPtr& data, int flags);
 	void GenDynamicSize(Output *out, Env *env, const DataPtr& data);