diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 24676ebc..3e9751ea 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,7 +25,7 @@ jobs:
       run: |
         mkdir -p build
         cd build
-        cmake -DCMAKE_BUILD_TYPE=${{ matrix.mode }} ..
+        ${{ matrix.env }} cmake -DCMAKE_BUILD_TYPE=${{ matrix.mode }} ..
         make
 
     - name: Check
diff --git a/src/polyxx/polynomial.cpp b/src/polyxx/polynomial.cpp
index aa0891ad..a71c51f7 100644
--- a/src/polyxx/polynomial.cpp
+++ b/src/polyxx/polynomial.cpp
@@ -377,29 +377,31 @@ namespace poly {
 
   std::vector<Polynomial> psc(const Polynomial& p, const Polynomial& q) {
     std::size_t size = std::min(degree(p), degree(q)) + 1;
-    lp_polynomial_t* tmp[size];
+    std::vector<lp_polynomial_t*> tmp;
     for (std::size_t i = 0; i < size; ++i) {
-      tmp[i] = lp_polynomial_new(detail::context(p, q));
+      tmp.push_back(lp_polynomial_new(detail::context(p, q)));
     }
-    lp_polynomial_psc(tmp, p.get_internal(), q.get_internal());
+    lp_polynomial_psc(tmp.data(), p.get_internal(), q.get_internal());
     std::vector<Polynomial> res;
     for (std::size_t i = 0; i < size; ++i) {
       res.emplace_back(tmp[i]);
     }
+    tmp.clear();
     return res;
   }
 
   std::vector<Polynomial> subres(const Polynomial& p, const Polynomial& q) {
     std::size_t size = std::min(degree(p), degree(q)) + 1;
-    lp_polynomial_t* tmp[size];
+    std::vector<lp_polynomial_t*> tmp;
     for (std::size_t i = 0; i < size; ++i) {
-      tmp[i] = lp_polynomial_new(detail::context(p, q));
+      tmp.push_back(lp_polynomial_new(detail::context(p, q)));
     }
-    lp_polynomial_subres(tmp, p.get_internal(), q.get_internal());
+    lp_polynomial_subres(tmp.data(), p.get_internal(), q.get_internal());
     std::vector<Polynomial> res;
     for (std::size_t i = 0; i < size; ++i) {
       res.emplace_back(tmp[i]);
     }
+    tmp.clear();
     return res;
   }
 
diff --git a/src/polyxx/upolynomial.cpp b/src/polyxx/upolynomial.cpp
index 90c21c1f..935b51a3 100644
--- a/src/polyxx/upolynomial.cpp
+++ b/src/polyxx/upolynomial.cpp
@@ -100,16 +100,19 @@ namespace poly {
   }
 
   std::vector<Integer> coefficients(const UPolynomial& p) {
-    lp_integer_t coeffs[degree(p) + 1];
+    std::vector<lp_integer_t> coeffs;
+    lp_integer_t tmp;
     for (std::size_t i = 0; i < degree(p) + 1; ++i) {
-      lp_integer_construct_from_int(lp_Z, &coeffs[i], 0);
+      lp_integer_construct_from_int(lp_Z, &tmp, 0);
+      coeffs.push_back(tmp);
     }
-    lp_upolynomial_unpack(p.get_internal(), coeffs);
+    lp_upolynomial_unpack(p.get_internal(), coeffs.data());
     std::vector<Integer> res;
     for (std::size_t i = 0; i < degree(p) + 1; ++i) {
       res.emplace_back(&coeffs[i]);
       lp_integer_destruct(&coeffs[i]);
     }
+    coeffs.clear();
     return res;
   }