diff --git a/btparser/types.cpp b/btparser/types.cpp
index 824b80e..9b3a9b3 100644
--- a/btparser/types.cpp
+++ b/btparser/types.cpp
@@ -11,7 +11,7 @@ using namespace Types;
 
 TypeManager::TypeManager(size_t pointerSize)
 {
-    auto p = [this](const std::string & n, Primitive p, int size)
+    auto p = [this](const std::string & n, Primitive p, size_t size)
     {
         primitivesizes[p] = size;
         auto splits = StringUtils::Split(n, ',');
@@ -96,7 +96,7 @@ bool TypeManager::AddUnion(const std::string & owner, const std::string & name)
     return addStructUnion(u);
 }
 
-bool TypeManager::AddMember(const std::string & parent, const QualifiedType& type, const std::string & name, int arrsize, int offset)
+bool TypeManager::AddMember(const std::string & parent, const QualifiedType& type, const std::string & name, size_t arrsize, int offset)
 {
     if(!isDefined(type.name))
         return false;
@@ -129,7 +129,7 @@ bool TypeManager::AddMember(const std::string & parent, const QualifiedType& typ
             pad.type = QualifiedType("char");
             pad.arrsize = offset - s.size;
             char padname[32] = "";
-            sprintf_s(padname, "padding%d", pad.arrsize);
+            sprintf_s(padname, "padding%zu", pad.arrsize);
             pad.name = padname;
             s.members.push_back(pad);
             s.size += pad.arrsize;
@@ -150,7 +150,7 @@ bool TypeManager::AddMember(const std::string & parent, const QualifiedType& typ
     return true;
 }
 
-bool TypeManager::AppendMember(const QualifiedType& type, const std::string & name, int arrsize, int offset)
+bool TypeManager::AppendMember(const QualifiedType& type, const std::string & name, size_t arrsize, int offset)
 {
     return AddMember(laststruct, type, name, arrsize, offset);
 }
@@ -213,7 +213,7 @@ bool TypeManager::AppendArg(const QualifiedType& type, const std::string & name)
     return AddArg(lastfunction, type, name);
 }
 
-int TypeManager::Sizeof(const std::string& type) const
+size_t TypeManager::Sizeof(const std::string& type) const
 {
     auto foundT = types.find(type);
     if(foundT != types.end())
@@ -227,7 +227,7 @@ int TypeManager::Sizeof(const std::string& type) const
     return 0;
 }
 
-int TypeManager::Sizeof(const QualifiedType& type) const
+size_t TypeManager::Sizeof(const QualifiedType& type) const
 {
     if (type.isPointer())
         return primitivesizes.at(Pointer);
diff --git a/btparser/types.h b/btparser/types.h
index 078094a..f0ba339 100644
--- a/btparser/types.h
+++ b/btparser/types.h
@@ -32,7 +32,7 @@ namespace Types
         std::string owner; //Type owner
         std::string name; //Type identifier.
         Primitive primitive = Void; //Primitive type.
-        int size = 0; //Size in bytes.
+        size_t size = 0; //Size in bytes.
     };
 
     struct QualifiedType
@@ -91,7 +91,7 @@ namespace Types
     {
         std::string name; //Member identifier
         QualifiedType type; // Qualified Type
-        int arrsize = 0; //Number of elements if Member is an array (unused for function arguments)
+        size_t arrsize = 0; //Number of elements if Member is an array (unused for function arguments)
         int offset = -1; //Member offset (only stored for reference)
     };
 
@@ -122,7 +122,7 @@ namespace Types
         std::vector<Member> members; //StructUnion members
         std::vector<Function> vtable;
         bool isunion = false; //Is this a union?
-        int size = 0;
+        size_t size = 0;
     };
 
     struct EnumValue
@@ -164,7 +164,7 @@ namespace Types
             std::string kind;
             std::string name;
             std::string owner;
-            int size = 0;
+            size_t size = 0;
         };
 
         explicit TypeManager(size_t pointerSize);
@@ -173,14 +173,14 @@ namespace Types
         bool AddEnum(const std::string& owner, const std::string& name, const std::string & type);
         bool AddStruct(const std::string & owner, const std::string & name);
         bool AddUnion(const std::string & owner, const std::string & name);
-        bool AddMember(const std::string & parent, const QualifiedType & type, const std::string & name, int arrsize = 0, int offset = -1);
-        bool AppendMember(const QualifiedType & type, const std::string & name, int arrsize = 0, int offset = -1);
+        bool AddMember(const std::string & parent, const QualifiedType & type, const std::string & name, size_t arrsize = 0, int offset = -1);
+        bool AppendMember(const QualifiedType & type, const std::string & name, size_t arrsize = 0, int offset = -1);
         bool AddFunction(const std::string & owner, const std::string & name, const QualifiedType& rettype, CallingConvention callconv = Cdecl, bool noreturn = false, bool typeonly = false);
         bool AddEnumerator(const std::string& enumType, const std::string& name, uint64_t value);
         bool AddArg(const std::string & function, const QualifiedType & type, const std::string & name);
         bool AppendArg(const QualifiedType& type, const std::string & name);
-        int Sizeof(const QualifiedType& type) const;
-        int Sizeof(const std::string& type) const;
+        size_t Sizeof(const QualifiedType& type) const;
+        size_t Sizeof(const std::string& type) const;
         bool Visit(const std::string & type, const std::string & name, Visitor & visitor) const;
         void Clear(const std::string & owner = "");
         bool RemoveType(const std::string & type);
@@ -191,7 +191,7 @@ namespace Types
         bool GenerateStubs() const;
 
     private:
-        std::unordered_map<Primitive, int> primitivesizes;
+        std::unordered_map<Primitive, size_t> primitivesizes;
         std::unordered_map<Primitive, std::string> primitivenames;
         std::unordered_map<std::string, Type> types;
         std::unordered_map<std::string, Types::Enum> enums;