diff --git a/CMakeLists.txt b/CMakeLists.txt
index 91d26a9..6363173 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,8 +4,8 @@ project(kabufuda)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-include_directories(include)
-set(KABUFUDA_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/include CACHE PATH "kabufuda include path" FORCE)
+unset(KABUFUDA_INCLUDE_DIR CACHE)
+#set(KABUFUDA_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/include CACHE PATH "kabufuda include path" FORCE)
 
 unset(PLAT_SRCS)
 if(WIN32)
@@ -25,5 +25,6 @@ add_library(kabufuda STATIC
     include/kabufuda/SRAM.hpp lib/kabufuda/SRAM.cpp
     include/kabufuda/WideStringConvert.hpp lib/kabufuda/WideStringConvert.cpp
     ${PLAT_SRCS})
+target_include_directories(kabufuda PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>)
 
 add_subdirectory(test)
diff --git a/include/kabufuda/Card.hpp b/include/kabufuda/Card.hpp
index 7bd549e..150da23 100644
--- a/include/kabufuda/Card.hpp
+++ b/include/kabufuda/Card.hpp
@@ -24,7 +24,7 @@ class FileHandle {
 public:
   FileHandle() = default;
   uint32_t getFileNo() const { return idx; }
-  operator bool() const { return getFileNo() != -1; }
+  operator bool() const { return getFileNo() != UINT32_MAX; }
 };
 
 struct ProbeResults {
diff --git a/include/kabufuda/Util.hpp b/include/kabufuda/Util.hpp
index 4fc10b0..eb3d884 100644
--- a/include/kabufuda/Util.hpp
+++ b/include/kabufuda/Util.hpp
@@ -119,13 +119,15 @@ static inline int32_t SBig(int32_t val) { return bswap32(val); }
 static inline uint32_t SBig(uint32_t val) { return bswap32(val); }
 static inline int64_t SBig(int64_t val) { return bswap64(val); }
 static inline uint64_t SBig(uint64_t val) { return bswap64(val); }
-static inline float SBig(float val) {
-  int32_t ival = bswap32(*((int32_t*)(&val)));
-  return *((float*)(&ival));
+inline float SBig(float val) {
+  union { float f; int32_t i; } uval1 = {val};
+  union { int32_t i; float f; } uval2 = {bswap32(uval1.i)};
+  return uval2.f;
 }
-static inline double SBig(double val) {
-  int64_t ival = bswap64(*((int64_t*)(&val)));
-  return *((double*)(&ival));
+inline double SBig(double val) {
+  union { double f; int64_t i; } uval1 = {val};
+  union { int64_t i; double f; } uval2 = {bswap64(uval1.i)};
+  return uval2.f;
 }
 #ifndef SBIG
 #define SBIG(q) (((q)&0x000000FF) << 24 | ((q)&0x0000FF00) << 8 | ((q)&0x00FF0000) >> 8 | ((q)&0xFF000000) >> 24)
diff --git a/lib/kabufuda/Card.cpp b/lib/kabufuda/Card.cpp
index a07934d..41f5997 100644
--- a/lib/kabufuda/Card.cpp
+++ b/lib/kabufuda/Card.cpp
@@ -564,12 +564,12 @@ ECardResult Card::getStatus(uint32_t fileNo, CardStat& statOut) const {
   statOut.x36_iconSpeed = file->m_animSpeed;
   statOut.x38_commentAddr = file->m_commentAddr;
 
-  if (file->m_iconAddress == -1) {
-    statOut.x3c_offsetBanner = -1;
-    statOut.x40_offsetBannerTlut = -1;
+  if (file->m_iconAddress == UINT32_MAX) {
+    statOut.x3c_offsetBanner = UINT32_MAX;
+    statOut.x40_offsetBannerTlut = UINT32_MAX;
     for (int i = 0; i < CARD_ICON_MAX; ++i)
-      statOut.x44_offsetIcon[i] = -1;
-    statOut.x64_offsetIconTlut = -1;
+      statOut.x44_offsetIcon[i] = UINT32_MAX;
+    statOut.x64_offsetIconTlut = UINT32_MAX;
     statOut.x68_offsetData = file->m_commentAddr + 64;
   } else {
     uint32_t cur = file->m_iconAddress;
@@ -589,7 +589,7 @@ ECardResult Card::getStatus(uint32_t fileNo, CardStat& statOut) const {
       statOut.x64_offsetIconTlut = cur;
       cur += TlutSize(EImageFormat::C8);
     } else
-      statOut.x64_offsetIconTlut = -1;
+      statOut.x64_offsetIconTlut = UINT32_MAX;
     statOut.x68_offsetData = cur;
   }