diff --git a/src/ast/normal_forms/nnf.cpp b/src/ast/normal_forms/nnf.cpp
index 7368d7935..f625095d0 100644
--- a/src/ast/normal_forms/nnf.cpp
+++ b/src/ast/normal_forms/nnf.cpp
@@ -216,6 +216,8 @@ struct nnf::imp {
             m_cache_result(cache_res),
             m_spos(spos) {
         }
+        //frame():m_curr(*(ast_manager*)(nullptr)) {
+        //}
     };
 
     // There are four caches:
diff --git a/src/util/util.h b/src/util/util.h
index f8c464197..6d38231ba 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -54,6 +54,7 @@ static_assert(sizeof(int64) == 8, "64 bits");
 #ifdef _WINDOWS
 #define SSCANF sscanf_s
 #define SPRINTF sprintf_s
+#define _Exit exit
 #else
 #define SSCANF sscanf
 #define SPRINTF sprintf