diff --git a/reactos/lib/sdk/crt/process/_system.c b/reactos/lib/sdk/crt/process/_system.c
index 94bbe7fcda4..f6173db03c6 100644
--- a/reactos/lib/sdk/crt/process/_system.c
+++ b/reactos/lib/sdk/crt/process/_system.c
@@ -108,7 +108,7 @@ int system(const char *command)
   CloseHandle(ProcessInformation.hThread);
 
 // system should wait untill the calling process is finished
-  _cwait(&nStatus,(int)ProcessInformation.hProcess,0);
+  _cwait(&nStatus,(intptr_t)ProcessInformation.hProcess,0);
   CloseHandle(ProcessInformation.hProcess);
 
   return nStatus;
diff --git a/reactos/lib/sdk/crt/process/process.c b/reactos/lib/sdk/crt/process/process.c
index 24b97408fdc..99b3208ea87 100644
--- a/reactos/lib/sdk/crt/process/process.c
+++ b/reactos/lib/sdk/crt/process/process.c
@@ -182,7 +182,7 @@ valisttosT(const _TCHAR* arg0, va_list alist, _TCHAR delim)
    return str;
 }
 
-static int
+static intptr_t
 do_spawnT(int mode, const _TCHAR* cmdname, const _TCHAR* args, const _TCHAR* envp)
 {
    STARTUPINFO StartupInfo = {0};
@@ -304,7 +304,7 @@ do_spawnT(int mode, const _TCHAR* cmdname, const _TCHAR* args, const _TCHAR* env
    {
       case _P_NOWAIT:
       case _P_NOWAITO:
-         return((int)ProcessInformation.hProcess);
+         return((intptr_t)ProcessInformation.hProcess);
       case _P_OVERLAY:
          CloseHandle(ProcessInformation.hProcess);
          _exit(0);
@@ -317,7 +317,7 @@ do_spawnT(int mode, const _TCHAR* cmdname, const _TCHAR* args, const _TCHAR* env
          CloseHandle(ProcessInformation.hProcess);
          return( 0);
    }
-   return( (int)ProcessInformation.hProcess);
+   return( (intptr_t)ProcessInformation.hProcess);
 }
 
 /*
diff --git a/reactos/lib/sdk/crt/stdio/lnx_vfprintf.c b/reactos/lib/sdk/crt/stdio/lnx_vfprintf.c
index c2a288496d6..613413df6a2 100644
--- a/reactos/lib/sdk/crt/stdio/lnx_vfprintf.c
+++ b/reactos/lib/sdk/crt/stdio/lnx_vfprintf.c
@@ -788,7 +788,7 @@ int __vfprintf(FILE *f, const char *fmt, va_list args)
 				flags |= ZEROPAD;
 			}
 			result = number(f,
-				        (unsigned long) va_arg(args, void *), 16,
+				        (uintptr_t) va_arg(args, void *), 16,
 					field_width, precision, flags);
 			if (result < 0)
 				return -1;
diff --git a/reactos/lib/sdk/crt/stdio/lnx_vfwprint.c b/reactos/lib/sdk/crt/stdio/lnx_vfwprint.c
index c6a494dd1f6..9df0b652538 100644
--- a/reactos/lib/sdk/crt/stdio/lnx_vfwprint.c
+++ b/reactos/lib/sdk/crt/stdio/lnx_vfwprint.c
@@ -761,7 +761,7 @@ int __vfwprintf(FILE *f, const wchar_t *fmt, va_list args)
 				flags |= ZEROPAD;
 			}
 			result = number(f,
-				        (unsigned long) va_arg(args, void *), 16,
+				        (uintptr_t) va_arg(args, void *), 16,
 					field_width, precision, flags);
 			if (result < 0)
 				return -1;
diff --git a/reactos/lib/sdk/crt/string/ctype.c b/reactos/lib/sdk/crt/string/ctype.c
index 9a74204d75e..46870724404 100644
--- a/reactos/lib/sdk/crt/string/ctype.c
+++ b/reactos/lib/sdk/crt/string/ctype.c
@@ -1,4 +1,6 @@
 #include <string.h>
+#undef __MINGW_IMPORT
+#define __MINGW_IMPORT
 #include <ctype.h>
 
 #undef _pctype