diff --git a/src/common/string.cpp b/src/common/string.cpp
index 20608e466b..f222417109 100644
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -1710,6 +1710,8 @@ bool wxString::ToDouble(double *val) const
 {
     wxCHECK_MSG( val, false, _T("NULL pointer in wxString::ToDouble") );
 
+    errno = 0;
+
     const wxChar *start = c_str();
     wxChar *end;
     *val = wxStrtod(start, &end);