diff --git a/src/sat/sat_clause.cpp b/src/sat/sat_clause.cpp
index 7b8abf6fb..eb51cb6ac 100644
--- a/src/sat/sat_clause.cpp
+++ b/src/sat/sat_clause.cpp
@@ -125,7 +125,9 @@ namespace sat {
         m_allocator("clause-allocator") {
 #if defined(_AMD64_) 
         m_num_segments = 0;
+#if defined(Z3DEBUG)
         m_overflow_valid = false;
+#endif
 #endif
     }