diff --git a/ebml/EbmlDate.h b/ebml/EbmlDate.h
index 8153fd50..6c3b5775 100644
--- a/ebml/EbmlDate.h
+++ b/ebml/EbmlDate.h
@@ -22,7 +22,7 @@ class EBML_DLL_API EbmlDate : public EbmlElementDefaultSameStorage<std::int64_t>
     {
       if (classInfo.HasDefault())
       {
-        auto def = static_cast<const EbmlCallbacksWithDefault<std::int64_t> &>(classInfo);
+        const auto& def = static_cast<const EbmlCallbacksWithDefault<std::int64_t> &>(classInfo);
         SetValue(def.DefaultValue());
       }
     }
diff --git a/ebml/EbmlElement.h b/ebml/EbmlElement.h
index 9282463a..263a7b13 100644
--- a/ebml/EbmlElement.h
+++ b/ebml/EbmlElement.h
@@ -430,7 +430,7 @@ static inline EbmlElement & tEBML_SEM_CREATE(const EbmlSemantic & s)
   return s.Create();
 }
 
-using _GetSemanticContext = const class EbmlSemanticContext &(*)();
+using _GetSemanticContext = const EbmlSemanticContext &(*)();
 
 /*!
   Context of the element
@@ -650,7 +650,7 @@ class EBML_DLL_API EbmlElement {
 
   private:
     std::size_t HeadSize() const {
-      return EBML_ID_LENGTH((const EbmlId&)*this) + CodedSizeLength(Size, SizeLength, bSizeIsFinite);
+      return EBML_ID_LENGTH(static_cast<const EbmlId&>(*this)) + CodedSizeLength(Size, SizeLength, bSizeIsFinite);
     } /// return the size of the head, on reading/writing
 
     std::uint64_t Size;        ///< the size of the data to write
diff --git a/src/EbmlElement.cpp b/src/EbmlElement.cpp
index 5526ac81..b05ea67b 100644
--- a/src/EbmlElement.cpp
+++ b/src/EbmlElement.cpp
@@ -195,23 +195,22 @@ EbmlElement * EbmlElement::FindNextID(IOCallback & DataStream, const EbmlCallbac
     } while (_SizeLength == 0);
   }
 
-  const auto PossibleID = EbmlId(EbmlId::FromBuffer(PossibleId.data(), PossibleID_Length));
-  auto Result = [=] {
-    if (PossibleID != EBML_INFO_ID(ClassInfos))
-    {
+  auto Result = [&]() -> EbmlElement * {
+    auto pID = EbmlId(EbmlId::FromBuffer(PossibleId.data(), PossibleID_Length));
+    if (pID != EBML_INFO_ID(ClassInfos)) {
       if (SizeFound == SizeUnknown)
-        return static_cast<EbmlElement *>(nullptr);
-      return static_cast<EbmlElement *>(new EbmlDummy(PossibleID));
+        return nullptr;
+      return new EbmlDummy(pID);
     }
     if (SizeFound != SizeUnknown && MaxDataSize < SizeFound)
-      return static_cast<EbmlElement *>(nullptr);
+      return nullptr;
     // check if the size is not all 1s
     if (SizeFound == SizeUnknown && !ClassInfos.CanHaveInfiniteSize())
-      return static_cast<EbmlElement *>(nullptr);
+      return nullptr;
     return &EBML_INFO_CREATE(ClassInfos);
   }();
 
-  if (Result == nullptr)
+  if (!Result)
     return nullptr;
 
   if (!Result->SizeIsValid(SizeFound)) {
@@ -454,7 +453,7 @@ EbmlElement *EbmlElement::CreateElementUsingContext(const EbmlId & aID, const Eb
 
   // parent elements
   if (EBML_CTX_MASTER(Context) != nullptr && aID == EBML_INFO_ID(*EBML_CTX_MASTER(Context))) {
-    auto Callbacks = *EBML_CTX_MASTER(Context);
+    const auto& Callbacks = *EBML_CTX_MASTER(Context);
     if (AsInfiniteSize && !Callbacks.CanHaveInfiniteSize())
       return nullptr;
     LowLevel++; // already one level up (same as context)
@@ -518,7 +517,7 @@ filepos_t EbmlElement::MakeRenderHead(IOCallback & output, bool bKeepPosition)
   std::array<binary, 4 + 8> FinalHead; // Class D + 64 bits coded size
   std::size_t FinalHeadSize;
 
-  FinalHeadSize = EBML_ID_LENGTH((const EbmlId&)*this);
+  FinalHeadSize = EBML_ID_LENGTH(static_cast<const EbmlId&>(*this));
   EbmlId(*this).Fill(FinalHead.data());
 
   const unsigned int CodedSize = CodedSizeLength(Size, SizeLength, bSizeIsFinite);
diff --git a/src/EbmlFloat.cpp b/src/EbmlFloat.cpp
index 3160454b..0d9ae786 100644
--- a/src/EbmlFloat.cpp
+++ b/src/EbmlFloat.cpp
@@ -19,7 +19,7 @@ EbmlFloat::EbmlFloat(const EbmlCallbacksDefault<double> & classInfo, const EbmlF
   SetPrecision(prec);
   if (classInfo.HasDefault())
   {
-    auto def = static_cast<const EbmlCallbacksWithDefault<double> &>(classInfo);
+    const auto& def = static_cast<const EbmlCallbacksWithDefault<double> &>(classInfo);
     SetValue(def.DefaultValue());
   }
 }
diff --git a/src/EbmlMaster.cpp b/src/EbmlMaster.cpp
index 31132842..7a27919b 100644
--- a/src/EbmlMaster.cpp
+++ b/src/EbmlMaster.cpp
@@ -104,7 +104,7 @@ std::uint64_t EbmlMaster::UpdateSize(const ShouldWrite & writeFilter, bool bForc
   SetSize_(0);
 
   if (!IsFiniteSize())
-    return (0-1);
+    return std::numeric_limits<std::uint64_t>::max();
 
   if (!bForceRender) {
     assert(CheckMandatory());
@@ -117,7 +117,7 @@ std::uint64_t EbmlMaster::UpdateSize(const ShouldWrite & writeFilter, bool bForc
     const std::uint64_t SizeToAdd = Element->ElementSize(writeFilter);
 #if !defined(NDEBUG)
     if (static_cast<std::int64_t>(SizeToAdd) == (0-1))
-      return (0-1);
+      return std::numeric_limits<std::uint64_t>::max();
 #endif // !NDEBUG
     SetSize_(GetSize() + SizeToAdd);
   }
diff --git a/src/EbmlSInteger.cpp b/src/EbmlSInteger.cpp
index edd4a854..ab6d19e6 100644
--- a/src/EbmlSInteger.cpp
+++ b/src/EbmlSInteger.cpp
@@ -34,7 +34,7 @@ EbmlSInteger::EbmlSInteger(const EbmlCallbacksDefault<std::int64_t> & classInfo)
 {
   if (classInfo.HasDefault())
   {
-    auto def = static_cast<const EbmlCallbacksWithDefault<std::int64_t> &>(classInfo);
+    const auto& def = static_cast<const EbmlCallbacksWithDefault<std::int64_t> &>(classInfo);
     SetValue(def.DefaultValue());
   }
 }
diff --git a/src/EbmlString.cpp b/src/EbmlString.cpp
index fec753f0..ac2fdab6 100644
--- a/src/EbmlString.cpp
+++ b/src/EbmlString.cpp
@@ -15,7 +15,7 @@ EbmlString::EbmlString(const EbmlCallbacksDefault<const char *> & classInfo)
 {
   if (classInfo.HasDefault())
   {
-    auto def = static_cast<const EbmlCallbacksWithDefault<const char *> &>(classInfo);
+    const auto& def = static_cast<const EbmlCallbacksWithDefault<const char *> &>(classInfo);
     SetValue(def.DefaultValue());
   }
 }
diff --git a/src/EbmlUInteger.cpp b/src/EbmlUInteger.cpp
index 137d4af6..4ec8b5ca 100644
--- a/src/EbmlUInteger.cpp
+++ b/src/EbmlUInteger.cpp
@@ -17,7 +17,7 @@ EbmlUInteger::EbmlUInteger(const EbmlCallbacksDefault<std::uint64_t> & classInfo
 {
   if (classInfo.HasDefault())
   {
-    auto def = static_cast<const EbmlCallbacksWithDefault<std::uint64_t> &>(classInfo);
+    const auto& def = static_cast<const EbmlCallbacksWithDefault<std::uint64_t> &>(classInfo);
     SetValue(def.DefaultValue());
   }
 }
diff --git a/src/EbmlUnicodeString.cpp b/src/EbmlUnicodeString.cpp
index b45fa30c..22ccfae2 100644
--- a/src/EbmlUnicodeString.cpp
+++ b/src/EbmlUnicodeString.cpp
@@ -104,7 +104,7 @@ EbmlUnicodeString::EbmlUnicodeString(const EbmlCallbacksDefault<const wchar_t *>
 {
   if (classInfo.HasDefault())
   {
-    auto def = static_cast<const EbmlCallbacksWithDefault<const wchar_t *> &>(classInfo);
+    const auto& def = static_cast<const EbmlCallbacksWithDefault<const wchar_t *> &>(classInfo);
     SetValue(UTFstring{def.DefaultValue()});
   }
 }
diff --git a/src/MemIOCallback.cpp b/src/MemIOCallback.cpp
index 25c202df..eaacf7c2 100644
--- a/src/MemIOCallback.cpp
+++ b/src/MemIOCallback.cpp
@@ -91,7 +91,7 @@ std::size_t MemIOCallback::write(IOCallback & IOToRead, std::size_t Size)
   }
   IOToRead.readFully(&dataBuffer[dataBufferPos], Size);
   dataBufferTotalSize = Size;
-  return Size;
+  return static_cast<std::uint32_t>(Size);
 }
 
 } // namespace libebml
diff --git a/src/StdIOCallback.cpp b/src/StdIOCallback.cpp
index 083a8e07..d05c38c7 100644
--- a/src/StdIOCallback.cpp
+++ b/src/StdIOCallback.cpp
@@ -98,7 +98,7 @@ void StdIOCallback::setFilePointer(std::int64_t Offset,seek_mode Mode)
 std::size_t StdIOCallback::write(const void*Buffer,std::size_t Size)
 {
   assert(File!=nullptr);
-  const std::uint32_t Result = fwrite(Buffer,1,Size,File);
+  const size_t Result = fwrite(Buffer,1,Size,File);
   mCurrentPosition += Result;
   return Result;
 }
diff --git a/test/test_id.cxx b/test/test_id.cxx
index 17ce1c02..d95ce92f 100644
--- a/test/test_id.cxx
+++ b/test/test_id.cxx
@@ -9,13 +9,13 @@ static constexpr EbmlId MyId = EbmlId{0x654321};
 
 class KaxTracks {
 public:
-    static const EbmlId & ClassId() { return MyId; };
+    static const EbmlId & ClassId() { return MyId; }
 };
 
 int main(void)
 {
     constexpr binary buf[4] = { 0x12, 0x34, 0x56, 0x78 };
-    EbmlId frombuf(EbmlId::FromBuffer(buf, 4));
+    auto frombuf = EbmlId(EbmlId::FromBuffer(buf, 4));
 
     EbmlId fromint(0x12345678);
 
diff --git a/test/test_macros.cxx b/test/test_macros.cxx
index 8aeb96d3..c31cad81 100644
--- a/test/test_macros.cxx
+++ b/test/test_macros.cxx
@@ -56,7 +56,7 @@ int main(void)
         return 1;
 
     UIntWithDefault test0;
-    auto ClassSpecWithDefault = test0.ElementSpec();
+    const auto& ClassSpecWithDefault = test0.ElementSpec();
     if (!ClassSpecWithDefault.HasDefault())
         return 1;
 
@@ -90,7 +90,7 @@ int main(void)
         return 1;
 
     UIntWithoutDefault testNoDefault0;
-    auto ClassSpecWithoutDefault = testNoDefault0.ElementSpec();
+    const auto& ClassSpecWithoutDefault = testNoDefault0.ElementSpec();
     if (ClassSpecWithoutDefault.HasDefault())
         return 1;
 #ifdef TEST_COMPILATION_ERRORS
diff --git a/test/test_utfstring.cxx b/test/test_utfstring.cxx
index 8a7b4f23..33c78b11 100644
--- a/test/test_utfstring.cxx
+++ b/test/test_utfstring.cxx
@@ -36,7 +36,7 @@ int main(void)
     UTFstring invalid;
     invalid.SetUTF8( "\x1\xF6\x00" );
 
-    UTFstring empty{0};
+    UTFstring empty{nullptr};
     if (empty.length() != 0)
         return 1;