diff --git a/src/base/acb/acbXec.c b/src/base/acb/acbXec.c
index bfa99f86b..c37a5fe60 100644
--- a/src/base/acb/acbXec.c
+++ b/src/base/acb/acbXec.c
@@ -81,7 +81,7 @@ static inline word Acb_XecGiaLitWord( Vec_Wrd_t * vSims, int nWords, int Lit, in
     word Res = Vec_WrdEntry( vSims, Abc_Lit2Var(Lit) * nWords + w );
     return Abc_LitIsCompl(Lit) ? ~Res : Res;
 }
-int * Acb_NtkSolveCadicalLimit( Gia_Man_t * p, int fUseHeavyOpt, int fVerbose, int * pStatus, int nSatTimeLimit, char * pLabel, int fUseXecOutputClauses )
+int * Acb_NtkSolveCadicalLimit( Gia_Man_t * p, int fUseHeavyOpt, int fVerbose, int * pStatus, int nSatTimeLimit, const char * pLabel, int fUseXecOutputClauses )
 {
     Aig_Man_t * pMan = NULL;
     Cnf_Dat_t * pCnf = NULL;
diff --git a/src/base/acb/acbXec.h b/src/base/acb/acbXec.h
index 546913fab..c774f52af 100644
--- a/src/base/acb/acbXec.h
+++ b/src/base/acb/acbXec.h
@@ -59,7 +59,7 @@ static inline void Acb_XecMergeTargetStatus( int StatusTarget, int fHasModel, in
         *pStatus = ACB_XEC_NEQ;
 }
 
-extern int *      Acb_NtkSolveCadicalLimit( Gia_Man_t * p, int fUseHeavyOpt, int fVerbose, int * pStatus, int nSatTimeLimit, char * pLabel, int fUseXecOutputClauses );
+extern int *      Acb_NtkSolveCadicalLimit( Gia_Man_t * p, int fUseHeavyOpt, int fVerbose, int * pStatus, int nSatTimeLimit, const char * pLabel, int fUseXecOutputClauses );
 extern int        Acb_CnfCoDriverLit( Cnf_Dat_t * pCnf, int iCo, int * pLit );
 extern int        Acb_GiaAllPosConst0( Gia_Man_t * p );