diff --git a/dlls/advapi32/advapi32_misc.h b/dlls/advapi32/advapi32_misc.h
index 6ec18f698cc..4d0a0e901c5 100644
--- a/dlls/advapi32/advapi32_misc.h
+++ b/dlls/advapi32/advapi32_misc.h
@@ -24,7 +24,7 @@ const char * debugstr_sid(PSID sid);
 BOOL ADVAPI_IsLocalComputer(LPCWSTR ServerName);
 BOOL ADVAPI_GetComputerSid(PSID sid);
 
-BOOL lookup_local_wellknown_name(LSA_UNICODE_STRING*, PSID, LPDWORD, LPWSTR, LPDWORD, PSID_NAME_USE, BOOL*);
-BOOL lookup_local_user_name(LSA_UNICODE_STRING*, PSID, LPDWORD, LPWSTR, LPDWORD, PSID_NAME_USE, BOOL*);
+BOOL lookup_local_wellknown_name(const LSA_UNICODE_STRING*, PSID, LPDWORD, LPWSTR, LPDWORD, PSID_NAME_USE, BOOL*);
+BOOL lookup_local_user_name(const LSA_UNICODE_STRING*, PSID, LPDWORD, LPWSTR, LPDWORD, PSID_NAME_USE, BOOL*);
 
 #endif /* __WINE_ADVAPI32MISC_H */
diff --git a/dlls/advapi32/security.c b/dlls/advapi32/security.c
index 2338acae803..aa7f336ceac 100644
--- a/dlls/advapi32/security.c
+++ b/dlls/advapi32/security.c
@@ -2764,7 +2764,7 @@ static BOOL match_account( ULONG idx, const LSA_UNICODE_STRING *account )
 /*
  * Helper function for LookupAccountNameW
  */
-BOOL lookup_local_wellknown_name( LSA_UNICODE_STRING *account_and_domain,
+BOOL lookup_local_wellknown_name( const LSA_UNICODE_STRING *account_and_domain,
                                   PSID Sid, LPDWORD cbSid,
                                   LPWSTR ReferencedDomainName,
                                   LPDWORD cchReferencedDomainName,
@@ -2827,7 +2827,7 @@ BOOL lookup_local_wellknown_name( LSA_UNICODE_STRING *account_and_domain,
     return ret;
 }
 
-BOOL lookup_local_user_name( LSA_UNICODE_STRING *account_and_domain,
+BOOL lookup_local_user_name( const LSA_UNICODE_STRING *account_and_domain,
                              PSID Sid, LPDWORD cbSid,
                              LPWSTR ReferencedDomainName,
                              LPDWORD cchReferencedDomainName,