diff --git a/src/misc/util/abc_global.h b/src/misc/util/abc_global.h
index b666fca01..5e1651d2e 100644
--- a/src/misc/util/abc_global.h
+++ b/src/misc/util/abc_global.h
@@ -292,8 +292,8 @@ static inline int      Abc_Base2LogW( word n )                { int r; if ( n <
 static inline int      Abc_Base10LogW( word n )               { int r; if ( n < 2 ) return (int)n; for ( r = 0, n--; n; n /= 10, r++ ) {}; return r; }
 static inline int      Abc_Base16LogW( word n )               { int r; if ( n < 2 ) return (int)n; for ( r = 0, n--; n; n /= 16, r++ ) {}; return r; }
 static inline char *   Abc_UtilStrsav( char * s )             { return s ? strcpy(ABC_ALLOC(char, strlen(s)+1), s) : NULL;  }
-static inline char *   Abc_UtilStrsavTwo( char * s, char * a ){ char * r; if (!a) return Abc_UtilStrsav(s); r = ABC_ALLOC(char, strlen(s)+strlen(a)+1); sprintf(r, "%s%s", s, a ); return r; }
-static inline char *   Abc_UtilStrsavNum( char * s, int n )   { char * r; if (!s) return NULL;              r = ABC_ALLOC(char, strlen(s)+12+1);        sprintf(r, "%s%d", s, n ); return r; }
+static inline char *   Abc_UtilStrsavTwo( char * s, char * a ){ char * r; if (!a) return Abc_UtilStrsav(s); r = ABC_ALLOC(char, strlen(s)+strlen(a)+1); snprintf(r, strlen(s)+strlen(a)+1, "%s%s", s, a ); return r; }
+static inline char *   Abc_UtilStrsavNum( char * s, int n )   { char * r; if (!s) return NULL;              r = ABC_ALLOC(char, strlen(s)+12+1);        snprintf(r, strlen(s)+12+1, "%s%d", s, n ); return r; }
 static inline int      Abc_BitByteNum( int nBits )            { return (nBits>>3) + ((nBits&7)  > 0);                       }
 static inline int      Abc_BitWordNum( int nBits )            { return (nBits>>5) + ((nBits&31) > 0);                       }
 static inline int      Abc_Bit6WordNum( int nBits )           { return (nBits>>6) + ((nBits&63) > 0);                       }
diff --git a/src/misc/util/utilDouble.h b/src/misc/util/utilDouble.h
index 0d0237818..406ddf5c7 100644
--- a/src/misc/util/utilDouble.h
+++ b/src/misc/util/utilDouble.h
@@ -183,6 +183,8 @@ static inline void Xdbl_Test()
     xdbl ten100_ = ABC_CONST(0x014c924d692ca61b);
 
     assert( ten100 == ten100_ );
+    (void)ten100;
+    (void)ten100_;
 
 //    float f1 = Xdbl_ToDouble(c1);
 //    Extra_PrintBinary( stdout, (int *)&c1, 32 ); printf( "\n" );
diff --git a/src/misc/util/utilTruth.h b/src/misc/util/utilTruth.h
index 2d0422401..2d5282f96 100644
--- a/src/misc/util/utilTruth.h
+++ b/src/misc/util/utilTruth.h
@@ -1595,6 +1595,7 @@ static inline int Abc_TtReadBin( word * pWords, int nWords, char * pString )
 {
     int i, Len = (int)strlen(pString), nWords2 = (Len+63)/64;
     assert( nWords2 <= nWords );
+    (void)nWords2;
     memset( pWords, 0, sizeof(word)*nWords );
     for ( i = 0; i < Len; i++ )
         if ( pString[i] == '1' )
@@ -1608,6 +1609,7 @@ static inline word Abc_TtReadBin64( char * pString )
     word Word = 0;
     int Len = (int)strlen(pString);
     assert( Len <= 64 );
+    (void)Len;
     int Res = Abc_TtReadBin( &Word, 1, pString );
     if ( Res == 0 ) {
         printf( "Reading binary string \"%s\" has failed.\n", pString );
@@ -1842,6 +1844,7 @@ static inline int Abc_TtCheckCondDep( word * pTruth, int nVars, int nSuppLim )
     word Cof0[128], Cof1[128]; // pow( 2, nVarsMax-6 )
     int v, d, nWords = Abc_TtWordNum(nVars);
     assert( nVars <= nVarsMax );
+    (void)nVarsMax;
     if ( nVars <= nSuppLim + 1 )
         return 0;
     for ( v = 0; v < nVars; v++ )
diff --git a/src/misc/vec/vecMem.h b/src/misc/vec/vecMem.h
index eedd14f22..115478e9b 100644
--- a/src/misc/vec/vecMem.h
+++ b/src/misc/vec/vecMem.h
@@ -458,7 +458,7 @@ static inline void Vec_MemDumpTruthTables( Vec_Mem_t * p, char * pName, int nLut
 {
     FILE * pFile;
     char pFileName[1000];
-    sprintf( pFileName, "tt_%s_%02d.txt", pName ? pName : NULL, nLutSize );
+    snprintf( pFileName, sizeof(pFileName), "tt_%s_%02d.txt", pName ? pName : "", nLutSize );
     pFile = pName ? fopen( pFileName, "wb" ) : stdout;
     Vec_MemDump( pFile, p );
     if ( pFile != stdout )
@@ -475,4 +475,3 @@ ABC_NAMESPACE_HEADER_END
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
-
diff --git a/src/opt/ufar/UfarMgr.cpp b/src/opt/ufar/UfarMgr.cpp
index 373e1e322..ea565b5e4 100755
--- a/src/opt/ufar/UfarMgr.cpp
+++ b/src/opt/ufar/UfarMgr.cpp
@@ -525,6 +525,7 @@ Vec_Int_t * SimUifPairFinder::_collect_sim_nodes(Wlc_Ntk_t * pNtk) {
     int i;
     Wlc_Obj_t * pPo;
     int range = Wlc_ObjRange(Wlc_NtkPo(pNtk, 1));
+    (void)range;
     Wlc_NtkForEachPo(pNtk, pPo, i) {
        if ((i%3)==0) continue;
        assert(range == Wlc_ObjRange(pPo));
@@ -1419,7 +1420,7 @@ int UfarManager::PerformUIFProve(const timeval& timer) {
     auto print_stat = [&]() {
         gettimeofday(&curTime, NULL);
         elapsedTime = elapsed_time_usec(timer, curTime)/1000000.0;
-        sprintf(buffer, "Iteration[%2u][%3u]: %4lu White boxes\t%4lu UIF constraints (time = %.4f)", n_iter_wb, n_iter_uif, count(_vec_op_blackbox_marks.begin(), _vec_op_blackbox_marks.end(), false), _set_uif_pairs.size(), elapsedTime);
+        snprintf(buffer, sizeof(buffer), "Iteration[%2u][%3u]: %4lu White boxes\t%4lu UIF constraints (time = %.4f)", n_iter_wb, n_iter_uif, count(_vec_op_blackbox_marks.begin(), _vec_op_blackbox_marks.end(), false), _set_uif_pairs.size(), elapsedTime);
         LOG(1) << buffer << _get_profile_uf_wb();
         dump_grey_stat();
         if(!params.fileStatesOut.empty()) _dump_states(params.fileStatesOut);
diff --git a/src/opt/ufar/UfarMgr.h b/src/opt/ufar/UfarMgr.h
index d094db4e0..dad82f6a2 100755
--- a/src/opt/ufar/UfarMgr.h
+++ b/src/opt/ufar/UfarMgr.h
@@ -35,7 +35,7 @@ using IntPair = std::pair<int, int>;
 
 struct OperatorID;
 struct UifPair;
-struct Greyness;
+class Greyness;
 using  UIF_PAIR = UifPair;
 
 class SimUifPairFinder;