diff --git a/include/curl/curlbuild.h.dist b/include/curl/curlbuild.h.dist
index 60f5d749d2..ed284b0523 100644
--- a/include/curl/curlbuild.h.dist
+++ b/include/curl/curlbuild.h.dist
@@ -417,7 +417,7 @@
 /* ===================================== */
 
 #elif defined(_MSC_VER)
-#  if (_MSC_VER >= 900)
+#  if (_MSC_VER >= 900) && (_INTEGRAL_MAX_BITS >= 64)
 #    define CURL_SIZEOF_LONG        4
 #    define CURL_OFF_T              __int64
 #    define CURL_FORMAT_CURL_OFF_T  "I64d"
diff --git a/lib/mprintf.c b/lib/mprintf.c
index a358cc10a7..93982a5b19 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -65,7 +65,7 @@
 #  define LONG_LONG_TYPE long long
 #  define HAVE_LONG_LONG_TYPE
 #else
-#  if defined(_MSC_VER) && (_MSC_VER >= 900)
+#  if defined(_MSC_VER) && (_MSC_VER >= 900) && (_INTEGRAL_MAX_BITS >= 64)
 #    define LONG_LONG_TYPE __int64
 #    define HAVE_LONG_LONG_TYPE
 #  else
diff --git a/lib/strtoofft.h b/lib/strtoofft.h
index 6c1d944e10..6d7a14930f 100644
--- a/lib/strtoofft.h
+++ b/lib/strtoofft.h
@@ -45,7 +45,7 @@
 #  ifdef HAVE_STRTOLL
 #    define curlx_strtoofft strtoll
 #  else
-#    if defined(_MSC_VER) && (_MSC_VER >= 1300)
+#    if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_INTEGRAL_MAX_BITS >= 64)
        _CRTIMP __int64 __cdecl _strtoi64(const char *, char **, int);
 #      define curlx_strtoofft _strtoi64
 #    else