diff --git a/libs/wine/string.c b/libs/wine/string.c
index f2a9bd3c704..7aa981f0a62 100644
--- a/libs/wine/string.c
+++ b/libs/wine/string.c
@@ -19,6 +19,7 @@
  */
 
 #include <assert.h>
+#include <errno.h>
 #include <limits.h>
 #include <stdio.h>
 
@@ -162,6 +163,7 @@ long int strtolW( const WCHAR *nptr, WCHAR **endptr, int base )
 
   if (overflow)
     {
+      errno = ERANGE;
       return negative ? LONG_MIN : LONG_MAX;
     }
 
@@ -274,6 +276,7 @@ unsigned long int strtoulW( const WCHAR *nptr, WCHAR **endptr, int base )
 
   if (overflow)
     {
+      errno = ERANGE;
       return ULONG_MAX;
     }