1 files changed, 2 insertions, 2 deletions
diff --git a/src/utils/exceptn.h b/src/utils/exceptn.h
index 1177a4e7d..8c74420df 100644
--- a/src/utils/exceptn.h
+++ b/src/utils/exceptn.h
@@ -56,7 +56,7 @@ struct BOTAN_DLL Invalid_Key_Length : public Invalid_Argument
    {
    Invalid_Key_Length(const std::string& name, size_t length) :
       Invalid_Argument(name + " cannot accept a key of length " +
-                       to_string(length))
+                       std::to_string(length))
       {}
    };
 
@@ -78,7 +78,7 @@ struct BOTAN_DLL Invalid_Block_Size : public Invalid_Argument
 struct BOTAN_DLL Invalid_IV_Length : public Invalid_Argument
    {
    Invalid_IV_Length(const std::string& mode, size_t bad_len) :
-      Invalid_Argument("IV length " + to_string(bad_len) +
+      Invalid_Argument("IV length " + std::to_string(bad_len) +
                        " is invalid for " + mode)
       {}
    };