diff --git a/Source/exehead/exec.c b/Source/exehead/exec.c
index 4956985e..352df5fa 100644
--- a/Source/exehead/exec.c
+++ b/Source/exehead/exec.c
@@ -1406,7 +1406,6 @@ static int NSISCALL ExecuteEntry(entry *entry_)
 #endif
       {
         TCHAR *textout=var1;
-        DWORD dw;
         int rpos=0;
         TCHAR *hptr=var0;
         int maxlen=GetIntFromParm(2);
@@ -1427,17 +1426,17 @@ static int NSISCALL ExecuteEntry(entry *entry_)
               And what if the multibyte character needs two WCHARs?
               */
               char tmpc;
-              if (!ReadFile(h,&tmpc,1,&dw,NULL) || dw != 1) break;
+              if (!myReadFile(h,&tmpc,1)) break;
               if (0==MultiByteToWideChar(CP_ACP, 0, &tmpc, 1, &c, 1)) c = _T('?');
             }
             else
 #endif
             {
-              if (!ReadFile(h,&c,1,&dw,NULL) || dw != 1) break;
+              if (!myReadFile(h,&c,1)) break;
             }
             if (parm3)
             {
-              myitoa(textout,(unsigned int)(_TUCHAR)c);
+              myitoa(textout,(unsigned char)c);
               return 0;
             }
             if (lc == _T('\r') || lc == _T('\n'))
diff --git a/Source/exehead/fileform.c b/Source/exehead/fileform.c
index cc72dcb4..2d3dcb48 100644
--- a/Source/exehead/fileform.c
+++ b/Source/exehead/fileform.c
@@ -540,7 +540,7 @@ int NSISCALL _dodecomp(int offset, HANDLE hFileOut, unsigned char *outbuf, int o
   retval=__ensuredata(sizeof(int));
   if (retval<0) return retval;
 
-  if (!ReadFile(dbd_hFile,(LPVOID)&input_len,sizeof(int),&r,NULL) || r!=sizeof(int)) return -3;
+  if (!myReadFile(dbd_hFile,(LPVOID)&input_len,sizeof(int))) return -3;
   dbd_pos+=sizeof(int);
 
   retval=__ensuredata(input_len);
@@ -552,7 +552,7 @@ int NSISCALL _dodecomp(int offset, HANDLE hFileOut, unsigned char *outbuf, int o
     {
       DWORD t;
       DWORD l=min(input_len,IBUFSIZE);
-      if (!ReadFile(dbd_hFile,(LPVOID)_inbuffer,l,&r,NULL) || l != r) return -3;
+      if (!myReadFile(dbd_hFile,(LPVOID)_inbuffer,r=l)) return -3;
       if (!WriteFile(hFileOut,_inbuffer,r,&t,NULL) || t != l) return -2;
       retval+=r;
       input_len-=r;
@@ -571,8 +571,7 @@ int NSISCALL _dodecomp(int offset, HANDLE hFileOut, unsigned char *outbuf, int o
 
 BOOL NSISCALL ReadSelfFile(LPVOID lpBuffer, DWORD nNumberOfBytesToRead)
 {
-  DWORD rd;
-  return ReadFile(g_db_hFile,lpBuffer,nNumberOfBytesToRead,&rd,NULL) && (rd == nNumberOfBytesToRead);
+  return myReadFile(g_db_hFile,lpBuffer,nNumberOfBytesToRead);
 }
 
 DWORD NSISCALL SetSelfFilePointer(LONG lDistanceToMove)
diff --git a/Source/exehead/util.c b/Source/exehead/util.c
index c2c77e84..81cb2ef7 100644
--- a/Source/exehead/util.c
+++ b/Source/exehead/util.c
@@ -449,6 +449,13 @@ TCHAR * NSISCALL my_GetTempFileName(TCHAR *buf, const TCHAR *dir)
   return 0;
 }
 
+BOOL NSISCALL myReadFile(HANDLE h, LPVOID buf, DWORD cb)
+{
+	DWORD cbio;
+	BOOL r = ReadFile(h, buf, cb, &cbio, NULL);
+	return r && cb == cbio;
+}
+
 #ifdef NSIS_SUPPORT_MOVEONREBOOT
 /** Modifies the wininit.ini file to rename / delete a file.
  *
@@ -503,7 +510,7 @@ void RenameViaWininit(const TCHAR* prevName, const TCHAR* newName)
 
     if (pszWinInit != NULL)
     {
-      if (ReadFile(hfile, pszWinInit, dwFileSize, &dwBytes, NULL) && dwFileSize == dwBytes)
+      if (myReadFile(hfile, pszWinInit, dwFileSize))
       {
         // Look for the rename section in the current file.
         LPSTR pszRenameSecInFile = mystrstriA(pszWinInit, szRenameSec);
diff --git a/Source/exehead/util.h b/Source/exehead/util.h
index a81e02a4..f0c46b31 100644
--- a/Source/exehead/util.h
+++ b/Source/exehead/util.h
@@ -41,6 +41,7 @@ TCHAR * NSISCALL mystrcat(TCHAR *out, const TCHAR *concat);
 TCHAR * NSISCALL mystrstr(TCHAR *a, TCHAR *b);
 WIN32_FIND_DATA * NSISCALL file_exists(TCHAR *buf);
 TCHAR * NSISCALL my_GetTempFileName(TCHAR *buf, const TCHAR *dir);
+BOOL NSISCALL myReadFile(HANDLE h, LPVOID buf, DWORD cb);
 
 //BOOL NSISCALL my_SetWindowText(HWND hWnd, const TCHAR *val);
 #define my_SetWindowText SetWindowText