diff --git a/src/common/longlong.cpp b/src/common/longlong.cpp
index 62afbf79a4..aa40465563 100644
--- a/src/common/longlong.cpp
+++ b/src/common/longlong.cpp
@@ -1105,7 +1105,10 @@ void *wxULongLongWx::asArray(void) const
                                                                      \
         while ( ll != 0 )                                            \
         {                                                            \
-            result.Prepend((wxChar)(_T('0') + (ll % 10).ToLong()));  \
+            long digit = (ll % 10).ToLong();                         \
+            if ( neg )                                               \
+                digit = -digit;                                      \
+            result.Prepend((wxChar)(_T('0') + digit));               \
             ll /= 10;                                                \
         }                                                            \
                                                                      \
diff --git a/tests/longlong/longlongtest.cpp b/tests/longlong/longlongtest.cpp
index 5b7920bf87..043a259cef 100644
--- a/tests/longlong/longlongtest.cpp
+++ b/tests/longlong/longlongtest.cpp
@@ -303,6 +303,9 @@ void LongLongTestCase::ToString()
     a.Negate();
     CPPUNIT_ASSERT( a.ToString() == _T("-1311768467139281697") );
 
+    wxLongLong llMin(LONG_MIN, 0);
+    CPPUNIT_ASSERT( a.ToString() == _T("-9223372036854775808") );
+
 #if wxUSE_LONGLONG_WX
     wxLongLongWx a1(a.GetHi(), a.GetLo());
     CPPUNIT_ASSERT( a1.ToString() == _T("-1311768467139281697") );