diff --git a/src/kernel_hydro.h b/src/kernel_hydro.h
index 657dc3ddfcae5c37765bb85388091d9090c4b714..3662510fbcd3817d338d76bc89b1334e3c0cd395 100644
--- a/src/kernel_hydro.h
+++ b/src/kernel_hydro.h
@@ -236,18 +236,18 @@ static const vector kernel_igamma4_vec = FILL_VEC((float)kernel_igamma4);
 __attribute__((always_inline))
     INLINE static void kernel_deval_vec(vector *u, vector *w, vector *dw_dx) {
 
-  vector ind, c[kernel_degree + 1], x;
-  int j, k;
-
   /* Go to the range [0,1[ from [0,H[ */
+  vector x;
   x.v = u->v * kernel_igamma_vec.v;
 
   /* Load x and get the interval id. */
+  vector ind;
   ind.m = vec_ftoi(vec_fmin(x.v * kernel_ivals_vec.v, kernel_ivals_vec.v));
 
   /* load the coefficients. */
-  for (k = 0; k < VEC_SIZE; k++)
-    for (j = 0; j < kernel_degree + 1; j++)
+  vector c[kernel_degree + 1];
+  for (int k = 0; k < VEC_SIZE; k++)
+    for (int j = 0; j < kernel_degree + 1; j++)
       c[j].f[k] = kernel_coeffs[ind.i[k] * (kernel_degree + 1) + j];
 
   /* Init the iteration for Horner's scheme. */
diff --git a/src/vector.h b/src/vector.h
index 7c70f79e5a3001d34b455de49b6ab7f26cc104d3..fa311f121f7b702f2288be0d561e520b52330457 100644
--- a/src/vector.h
+++ b/src/vector.h
@@ -79,22 +79,12 @@
                             _mm512_set1_epi64(ptrs[0])),                    \
       1)
 #define vec_gather(base, offsets) _mm512_i32gather_ps(offsets.m, base, 1)
-#define FILL_VEC(constant) {.f[0] = constant, \
-                           .f[1] = constant, \
-                           .f[2] = constant, \
-                           .f[3] = constant, \
-                           .f[4] = constant, \
-                           .f[5] = constant, \
-                           .f[6] = constant, \
-                           .f[7] = constant, \
-                           .f[8] = constant, \
-                           .f[9] = constant, \
-                           .f[10] = constant, \
-                           .f[11] = constant, \
-                           .f[12] = constant, \
-                           .f[13] = constant, \
-                           .f[14] = constant, \
-                           .f[15] = constant}
+#define FILL_VEC(a)                                                     \
+  {                                                                     \
+    .f[0] = a, .f[1] = a, .f[2] = a, .f[3] = a, .f[4] = a, .f[5] = a,   \
+    .f[6] = a, .f[7] = a, .f[8] = a, .f[9] = a, .f[10] = a, .f[11] = a, \
+    .f[12] = a, .f[13] = a, .f[14] = a, .f[15] = a                      \
+  }
 #elif defined(NO__AVX__)
 #define VECTORIZE
 #define VEC_SIZE 8
@@ -123,14 +113,11 @@
 #define vec_dbl_ftoi(a) _mm256_cvttpd_epi32(a)
 #define vec_dbl_fmin(a, b) _mm256_min_pd(a, b)
 #define vec_dbl_fmax(a, b) _mm256_max_pd(a, b)
-#define FILL_VEC(constant) {.f[0] = constant, \
-                           .f[1] = constant, \
-                           .f[2] = constant, \
-                           .f[3] = constant, \
-                           .f[4] = constant, \
-                           .f[5] = constant, \
-                           .f[6] = constant, \
-                           .f[7] = constant}
+#define FILL_VEC(a)                                                   \
+  {                                                                   \
+    .f[0] = a, .f[1] = a, .f[2] = a, .f[3] = a, .f[4] = a, .f[5] = a, \
+    .f[6] = a, .f[7] = a                                              \
+  }
 #ifdef __AVX2__
 #define VEC_HAVE_GATHER
 #define vec_gather(base, offsets) _mm256_i32gather_ps(base, offsets.m, 1)
@@ -163,10 +150,8 @@
 #define vec_dbl_ftoi(a) _mm_cvttpd_epi32(a)
 #define vec_dbl_fmin(a, b) _mm_min_pd(a, b)
 #define vec_dbl_fmax(a, b) _mm_max_pd(a, b)
-#define FILL_VEC(constant) {.f[0] = constant, \
-                           .f[1] = constant, \
-                           .f[2] = constant, \
-                           .f[3] = constant}
+#define FILL_VEC(a) \
+  { .f[0] = a, .f[1] = a, .f[2] = a, .f[3] = a }
 #else
 #define VEC_SIZE 4
 #endif