diff --git a/src/util/mpz.h b/src/util/mpz.h
index 8f9548462..9e047929c 100644
--- a/src/util/mpz.h
+++ b/src/util/mpz.h
@@ -299,6 +299,7 @@ class mpz_manager {
 
     void set_i64(mpz & c, int64_t v) {
         if (v >= INT_MIN && v <= INT_MAX) {
+            deallocate(c);  // Free any existing large value before setting small
             c.set(static_cast<int>(v));             
         }
         else {
@@ -589,6 +590,7 @@ public:
 
     void set(mpz & target, mpz const & source) {
         if (is_small(source)) {
+            deallocate(target);  // Free any existing large value before setting small
             target.set(source.value());
         }
         else {
@@ -597,6 +599,7 @@ public:
     }
 
     void set(mpz & a, int val) {
+        deallocate(a);  // Free any existing large value before setting small
         a.set(val);
     }
 
@@ -615,6 +618,7 @@ public:
 
     void set(mpz & a, uint64_t val) {
         if (val < INT_MAX) {
+            deallocate(a);  // Free any existing large value before setting small
             a.set(static_cast<int>(val));
         }
         else {