diff --git a/src/aig/gia/giaIso3.c b/src/aig/gia/giaIso3.c
index 8bea4bbfae..b526676d36 100644
--- a/src/aig/gia/giaIso3.c
+++ b/src/aig/gia/giaIso3.c
@@ -177,7 +177,7 @@ Vec_Wec_t * Gia_Iso4Gia( Gia_Man_t * p )
     Vec_WecForEachLevel( vLevs, vLevel, l )
     {
         Gia_Obj_t * pObj;  int i;
-        int RandC[2] = { Abc_Random(0), Abc_Random(0) };
+        unsigned RandC[2] = { Abc_Random(0), Abc_Random(0) };
         if ( l == 0 )
         {
             Gia_ManForEachObjVec( vLevel, p, pObj, i )
diff --git a/src/base/acb/acbTest.c b/src/base/acb/acbTest.c
index 6290b88ea3..c22d4b55b3 100644
--- a/src/base/acb/acbTest.c
+++ b/src/base/acb/acbTest.c
@@ -421,8 +421,8 @@ Gia_Man_t * Acb_NtkGiaDeriveMiter( Gia_Man_t * pOne, Gia_Man_t * pTwo, int Type
     {
         for ( i = 0; i < Gia_ManCoNum(pOne); i += 2 )
         {
-            int pLitsF[2] = { Gia_ManCo(pOne, i)->Value, Gia_ManCo(pOne, i+1)->Value };
-            int pLitsS[2] = { Gia_ManCo(pTwo, i)->Value, Gia_ManCo(pTwo, i+1)->Value };
+            unsigned pLitsF[2] = { Gia_ManCo(pOne, i)->Value, Gia_ManCo(pOne, i+1)->Value };
+            unsigned pLitsS[2] = { Gia_ManCo(pTwo, i)->Value, Gia_ManCo(pTwo, i+1)->Value };
             Gia_ManAppendCo( pNew, pLitsF[0] );
             Gia_ManAppendCo( pNew, pLitsS[0] );
         }
@@ -431,8 +431,8 @@ Gia_Man_t * Acb_NtkGiaDeriveMiter( Gia_Man_t * pOne, Gia_Man_t * pTwo, int Type
     {
         for ( i = 0; i < Gia_ManCoNum(pOne); i += 2 )
         {
-            int pLitsF[2] = { Gia_ManCo(pOne, i)->Value, Gia_ManCo(pOne, i+1)->Value };
-            int pLitsS[2] = { Gia_ManCo(pTwo, i)->Value, Gia_ManCo(pTwo, i+1)->Value };
+            unsigned pLitsF[2] = { Gia_ManCo(pOne, i)->Value, Gia_ManCo(pOne, i+1)->Value };
+            unsigned pLitsS[2] = { Gia_ManCo(pTwo, i)->Value, Gia_ManCo(pTwo, i+1)->Value };
             Gia_ManAppendCo( pNew, pLitsF[1] );
             Gia_ManAppendCo( pNew, pLitsS[1] );
         }
@@ -441,8 +441,8 @@ Gia_Man_t * Acb_NtkGiaDeriveMiter( Gia_Man_t * pOne, Gia_Man_t * pTwo, int Type
     {
         for ( i = 0; i < Gia_ManCoNum(pOne); i += 2 )
         {
-            int pLitsF[2] = { Gia_ManCo(pOne, i)->Value, Gia_ManCo(pOne, i+1)->Value };
-            int pLitsS[2] = { Gia_ManCo(pTwo, i)->Value, Gia_ManCo(pTwo, i+1)->Value };
+            int pLitsF[2] = { (int)Gia_ManCo(pOne, i)->Value, (int)Gia_ManCo(pOne, i+1)->Value };
+            int pLitsS[2] = { (int)Gia_ManCo(pTwo, i)->Value, (int)Gia_ManCo(pTwo, i+1)->Value };
             Gia_ManAppendCo( pNew, Gia_ManDualCompare( pNew, pLitsF, pLitsS ) );
         }
     }
diff --git a/src/map/if/acd/ac_decomposition.hpp b/src/map/if/acd/ac_decomposition.hpp
index 8ba2fb20e2..8aee0266d6 100644
--- a/src/map/if/acd/ac_decomposition.hpp
+++ b/src/map/if/acd/ac_decomposition.hpp
@@ -40,6 +40,8 @@
 #include "kitty_operators.hpp"
 #include "kitty_static_tt.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace acd
 {
 
@@ -1303,4 +1305,6 @@ class ac_decomposition_impl
 
 } // namespace acd
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _ACD_H_
\ No newline at end of file
diff --git a/src/map/if/acd/ac_wrapper.cpp b/src/map/if/acd/ac_wrapper.cpp
index baeee2fd6a..fd8015f95e 100644
--- a/src/map/if/acd/ac_wrapper.cpp
+++ b/src/map/if/acd/ac_wrapper.cpp
@@ -19,6 +19,8 @@
 #include "ac_wrapper.h"
 #include "ac_decomposition.hpp"
 
+ABC_NAMESPACE_IMPL_START
+
 int acd_evaluate( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay, unsigned *cost, int try_no_late_arrival )
 {
   using namespace acd;
@@ -66,3 +68,5 @@ int acd_decompose( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay,
   acd.get_decomposition( decomposition );
   return 0;
 }
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/map/if/acd/ac_wrapper.h b/src/map/if/acd/ac_wrapper.h
index ce39949fb2..a384b4404b 100644
--- a/src/map/if/acd/ac_wrapper.h
+++ b/src/map/if/acd/ac_wrapper.h
@@ -23,15 +23,11 @@
 #include "misc/util/abc_global.h"
 #include "map/if/if.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+ABC_NAMESPACE_HEADER_START
 
 int acd_evaluate( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay, unsigned *cost, int try_no_late_arrival );
 int acd_decompose( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay, unsigned char *decomposition );
 
-#ifdef __cplusplus
-}
-#endif
+ABC_NAMESPACE_HEADER_END
 
 #endif
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_algorithm.hpp b/src/map/if/acd/kitty_algorithm.hpp
index 6460a802cf..78eead08a2 100644
--- a/src/map/if/acd/kitty_algorithm.hpp
+++ b/src/map/if/acd/kitty_algorithm.hpp
@@ -9,6 +9,8 @@
 #include "kitty_dynamic_tt.hpp"
 #include "kitty_static_tt.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -116,4 +118,6 @@ void for_each_block_reversed( const TT& tt, Fn&& op )
 
 } // namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_ALGORITHM_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_constants.hpp b/src/map/if/acd/kitty_constants.hpp
index 55cfcd650f..35ff489e90 100644
--- a/src/map/if/acd/kitty_constants.hpp
+++ b/src/map/if/acd/kitty_constants.hpp
@@ -5,6 +5,8 @@
 #include <cstdint>
 #include <vector>
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -88,4 +90,6 @@ static constexpr int32_t hex_to_int[] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
 
 } // namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif //_KITTY_CONSTANTS_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_constructors.hpp b/src/map/if/acd/kitty_constructors.hpp
index 43408b8cc3..26ec6e4835 100644
--- a/src/map/if/acd/kitty_constructors.hpp
+++ b/src/map/if/acd/kitty_constructors.hpp
@@ -12,6 +12,8 @@
 #include "kitty_dynamic_tt.hpp"
 #include "kitty_static_tt.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -89,4 +91,6 @@ void create_nth_var( TT& tt, uint8_t var_index, bool complement = false )
 
 } // namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_CONSTRUCT_TT_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_dynamic_tt.hpp b/src/map/if/acd/kitty_dynamic_tt.hpp
index f3ef0c7d9a..880943dfa6 100644
--- a/src/map/if/acd/kitty_dynamic_tt.hpp
+++ b/src/map/if/acd/kitty_dynamic_tt.hpp
@@ -8,6 +8,8 @@
 
 #include "kitty_constants.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -144,4 +146,6 @@ struct dynamic_truth_table
 
 } //namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_DYNAMIC_TT_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_operations.hpp b/src/map/if/acd/kitty_operations.hpp
index fb504489a4..bf8e38007e 100644
--- a/src/map/if/acd/kitty_operations.hpp
+++ b/src/map/if/acd/kitty_operations.hpp
@@ -14,6 +14,8 @@
 #include "kitty_dynamic_tt.hpp"
 #include "kitty_static_tt.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -330,4 +332,6 @@ void print_hex( const TT& tt, std::ostream& os = std::cout )
 
 } //namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_OPERATIONS_TT_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_operators.hpp b/src/map/if/acd/kitty_operators.hpp
index 68a24cf2ec..b5f4688c2c 100644
--- a/src/map/if/acd/kitty_operators.hpp
+++ b/src/map/if/acd/kitty_operators.hpp
@@ -13,6 +13,8 @@
 #include "kitty_static_tt.hpp"
 #include "kitty_operations.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -119,4 +121,6 @@ inline void operator|=( static_truth_table<NumVars>& first, const static_truth_t
 
 } // namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_OPERATORS_TT_H_
\ No newline at end of file
diff --git a/src/map/if/acd/kitty_static_tt.hpp b/src/map/if/acd/kitty_static_tt.hpp
index 61593f3ff1..ab5a5d1c93 100644
--- a/src/map/if/acd/kitty_static_tt.hpp
+++ b/src/map/if/acd/kitty_static_tt.hpp
@@ -7,6 +7,8 @@
 
 #include "kitty_constants.hpp"
 
+ABC_NAMESPACE_CXX_HEADER_START
+
 namespace kitty
 {
 
@@ -128,4 +130,6 @@ struct static_truth_table
 
 } //namespace kitty
 
+ABC_NAMESPACE_CXX_HEADER_END
+
 #endif // _KITTY_STATIC_TT_H_
\ No newline at end of file