diff --git a/reactos/lib/sdk/crt/string/strtol.c b/reactos/lib/sdk/crt/string/strtol.c
index 6e6706def8e..97932eb4c21 100644
--- a/reactos/lib/sdk/crt/string/strtol.c
+++ b/reactos/lib/sdk/crt/string/strtol.c
@@ -79,6 +79,7 @@ strtol(const char *nptr, char **endptr, int base)
   if (any < 0)
   {
     acc = neg ? LONG_MIN : LONG_MAX;
+    __set_errno(ERANGE);
   }
   else if (neg)
     acc = -acc;
diff --git a/reactos/lib/sdk/crt/string/strtoul.c b/reactos/lib/sdk/crt/string/strtoul.c
index 052d57a2c93..e386f5004a1 100644
--- a/reactos/lib/sdk/crt/string/strtoul.c
+++ b/reactos/lib/sdk/crt/string/strtoul.c
@@ -63,6 +63,7 @@ strtoul(const char *nptr, char **endptr, int base)
   if (any < 0)
   {
     acc = ULONG_MAX;
+    __set_errno(ERANGE);
   }
   else if (neg)
     acc = -acc;