diff --git a/src/hydro/Default/hydro_debug.h b/src/hydro/Default/hydro_debug.h
index 36eb75ae60e7a49ae798c232377985dd90cff54a..5b1648e222c36dc142362f26ad5188a2af397192 100644
--- a/src/hydro/Default/hydro_debug.h
+++ b/src/hydro/Default/hydro_debug.h
@@ -25,6 +25,7 @@ __attribute__((always_inline))
       "h=%.3e, "
       "wcount=%d, m=%.3e, dh_drho=%.3e, rho=%.3e, t_begin=%.3e, t_end=%.3e\n",
       p->x[0], p->x[1], p->x[2], p->v[0], p->v[1], p->v[2], xp->v_full[0],
-      xp->v_full[1], xp->v_full[2], p->a[0], p->a[1], p->a[2], 2. * p->h,
-      (int)p->density.wcount, p->mass, p->rho_dh, p->rho, p->t_begin, p->t_end);
+      xp->v_full[1], xp->v_full[2], p->a_hydro[0], p->a_hydro[1], p->a_hydro[2],
+      p->h, (int)p->density.wcount, p->mass, p->rho_dh, p->rho, p->t_begin,
+      p->t_end);
 }
diff --git a/src/hydro/Default/hydro_io.h b/src/hydro/Default/hydro_io.h
index fa25a600fd9c928eb27ce93d39d54f1af324df9e..e0debaa0d10f5c78f087d636efc4363eaf24f8d8 100644
--- a/src/hydro/Default/hydro_io.h
+++ b/src/hydro/Default/hydro_io.h
@@ -45,7 +45,7 @@ __attribute__((always_inline)) INLINE static void hydro_read_particles(
             COMPULSORY);
   readArray(h_grp, "ParticleIDs", ULONGLONG, N, 1, parts, N_total, offset, id,
             COMPULSORY);
-  readArray(h_grp, "Acceleration", FLOAT, N, 3, parts, N_total, offset, a,
+  readArray(h_grp, "Acceleration", FLOAT, N, 3, parts, N_total, offset, a_hydro,
             OPTIONAL);
   readArray(h_grp, "Density", FLOAT, N, 1, parts, N_total, offset, rho,
             OPTIONAL);
@@ -84,7 +84,7 @@ __attribute__((always_inline)) INLINE static void hydro_write_particles(
   writeArray(h_grp, fileName, xmfFile, "ParticleIDs", ULONGLONG, N, 1, parts,
              N_total, mpi_rank, offset, id, us, UNIT_CONV_NO_UNITS);
   writeArray(h_grp, fileName, xmfFile, "Acceleration", FLOAT, N, 3, parts,
-             N_total, mpi_rank, offset, a, us, UNIT_CONV_ACCELERATION);
+             N_total, mpi_rank, offset, a_hydro, us, UNIT_CONV_ACCELERATION);
   writeArray(h_grp, fileName, xmfFile, "Density", FLOAT, N, 1, parts, N_total,
              mpi_rank, offset, rho, us, UNIT_CONV_DENSITY);
 }
diff --git a/src/hydro/Default/hydro_part.h b/src/hydro/Default/hydro_part.h
index 2cb5345578f51ea6879f48d5e2adeba33a3d808e..ea316bb62a12ae0d3dd3fa8d2d8f89c85b63a246 100644
--- a/src/hydro/Default/hydro_part.h
+++ b/src/hydro/Default/hydro_part.h
@@ -44,7 +44,7 @@ struct part {
   float v[3];
 
   /* Particle acceleration. */
-  float a[3];
+  float a_hydro[3];
 
   /* Particle cutoff radius. */
   float h;
diff --git a/src/hydro/Gadget2/hydro.h b/src/hydro/Gadget2/hydro.h
index f14545d5ad995603b4c5474d91904c35fb118bad..3f0f15cbb83f2527bff6ab008a22effd34efd492 100644
--- a/src/hydro/Gadget2/hydro.h
+++ b/src/hydro/Gadget2/hydro.h
@@ -28,7 +28,9 @@ __attribute__((always_inline)) INLINE static float hydro_compute_timestep(
     struct part* p, struct xpart* xp) {
 
   /* Acceleration */
-  float ac = sqrtf(p->a[0] * p->a[0] + p->a[1] * p->a[1] + p->a[2] * p->a[2]);
+  float ac = sqrtf(p->a_hydro[0] * p->a_hydro[0] +
+		   p->a_hydro[1] * p->a_hydro[1] +
+		   p->a_hydro[2] * p->a_hydro[2]);
   ac = fmaxf(ac, 1e-30);
 
   const float dt_accel = sqrtf(2.f);  // MATTHIEU
@@ -164,9 +166,9 @@ __attribute__((always_inline))
     INLINE static void hydro_reset_acceleration(struct part* p) {
 
   /* Reset the acceleration. */
-  p->a[0] = 0.0f;
-  p->a[1] = 0.0f;
-  p->a[2] = 0.0f;
+  p->a_hydro[0] = 0.0f;
+  p->a_hydro[1] = 0.0f;
+  p->a_hydro[2] = 0.0f;
 
   p->force.h_dt = 0.0f;
 
diff --git a/src/hydro/Gadget2/hydro_debug.h b/src/hydro/Gadget2/hydro_debug.h
index 3d17c4f94191cec37521f7f1fd4aa1716c8f5fc2..5984e0bc98f707d63f25561a934f7479597b42b4 100644
--- a/src/hydro/Gadget2/hydro_debug.h
+++ b/src/hydro/Gadget2/hydro_debug.h
@@ -28,8 +28,8 @@ __attribute__((always_inline))
       "divV=%.3e, curlV=%.3e, rotV=[%.3e,%.3e,%.3e]  \n "
       "v_sig=%e t_begin=%.3e, t_end=%.3e\n",
       p->x[0], p->x[1], p->x[2], p->v[0], p->v[1], p->v[2], xp->v_full[0],
-      xp->v_full[1], xp->v_full[2], p->a[0], p->a[1], p->a[2], 2. * p->h,
-      (int)p->density.wcount, p->mass, p->rho_dh, p->rho, p->pressure,
+      xp->v_full[1], xp->v_full[2], p->a_hydro[0], p->a_hydro[1], p->a_hydro[2],
+      p->h, (int)p->density.wcount, p->mass, p->rho_dh, p->rho, p->pressure,
       p->entropy, p->entropy_dt, p->div_v, p->curl_v, p->rot_v[0], p->rot_v[1],
       p->rot_v[2], p->v_sig, p->t_begin, p->t_end);
 }
diff --git a/src/hydro/Gadget2/hydro_iact.h b/src/hydro/Gadget2/hydro_iact.h
index d8e555940002e7d7fcd5ae0791fe4348b5aff463..26e37a467e7fd1d0f7429d00303e19597e5a3fd8 100644
--- a/src/hydro/Gadget2/hydro_iact.h
+++ b/src/hydro/Gadget2/hydro_iact.h
@@ -272,13 +272,13 @@ __attribute__((always_inline)) INLINE static void runner_iact_force(
   /*   message("oO"); */
 
   /* Use the force Luke ! */
-  pi->a[0] -= acc * dx[0];
-  pi->a[1] -= acc * dx[1];
-  pi->a[2] -= acc * dx[2];
+  pi->a_hydro[0] -= acc * dx[0];
+  pi->a_hydro[1] -= acc * dx[1];
+  pi->a_hydro[2] -= acc * dx[2];
 
-  pj->a[0] += acc * dx[0];
-  pj->a[1] += acc * dx[1];
-  pj->a[2] += acc * dx[2];
+  pj->a_hydro[0] += acc * dx[0];
+  pj->a_hydro[1] += acc * dx[1];
+  pj->a_hydro[2] += acc * dx[2];
 
   /* Get the time derivative for h. */
   pi->force.h_dt -= mj * dvdr * r_inv / rhoj * wi_dr;
@@ -366,9 +366,9 @@ __attribute__((always_inline)) INLINE static void runner_iact_nonsym_force(
   const float acc = visc_term + sph_term;
 
   /* Use the force Luke ! */
-  pi->a[0] -= acc * dx[0];
-  pi->a[1] -= acc * dx[1];
-  pi->a[2] -= acc * dx[2];
+  pi->a_hydro[0] -= acc * dx[0];
+  pi->a_hydro[1] -= acc * dx[1];
+  pi->a_hydro[2] -= acc * dx[2];
 
   /* Get the time derivative for h. */
   pi->force.h_dt -= mj * dvdr * r_inv / rhoj * wi_dr;
diff --git a/src/hydro/Gadget2/hydro_io.h b/src/hydro/Gadget2/hydro_io.h
index 5e01d67fddcc81d766e8aa59eee2d6368378170c..ed450e77ad631ba14a14583fe17c8173652321c2 100644
--- a/src/hydro/Gadget2/hydro_io.h
+++ b/src/hydro/Gadget2/hydro_io.h
@@ -45,7 +45,7 @@ __attribute__((always_inline)) INLINE static void hydro_read_particles(
             entropy, COMPULSORY);
   readArray(h_grp, "ParticleIDs", ULONGLONG, N, 1, parts, N_total, offset, id,
             COMPULSORY);
-  readArray(h_grp, "Acceleration", FLOAT, N, 3, parts, N_total, offset, a,
+  readArray(h_grp, "Acceleration", FLOAT, N, 3, parts, N_total, offset, a_hydro,
             OPTIONAL);
   readArray(h_grp, "Density", FLOAT, N, 1, parts, N_total, offset, rho,
             OPTIONAL);
@@ -85,7 +85,7 @@ __attribute__((always_inline)) INLINE static void hydro_write_particles(
   writeArray(h_grp, fileName, xmfFile, "ParticleIDs", ULONGLONG, N, 1, parts,
              N_total, mpi_rank, offset, id, us, UNIT_CONV_NO_UNITS);
   writeArray(h_grp, fileName, xmfFile, "Acceleration", FLOAT, N, 3, parts,
-             N_total, mpi_rank, offset, a, us, UNIT_CONV_ACCELERATION);
+             N_total, mpi_rank, offset, a_hydro, us, UNIT_CONV_ACCELERATION);
   writeArray(h_grp, fileName, xmfFile, "Density", FLOAT, N, 1, parts, N_total,
              mpi_rank, offset, rho, us, UNIT_CONV_DENSITY);
 }
diff --git a/src/hydro/Gadget2/hydro_part.h b/src/hydro/Gadget2/hydro_part.h
index fea9ee54aaefbff0e7e5c8dfdb96950cbe5592ac..f7971605bf11dd00215ca12863670b1cc6ea95e1 100644
--- a/src/hydro/Gadget2/hydro_part.h
+++ b/src/hydro/Gadget2/hydro_part.h
@@ -41,7 +41,7 @@ struct part {
   float v[3];
 
   /* Particle acceleration. */
-  float a[3];
+  float a_hydro[3];
 
   /* Particle cutoff radius. */
   float h;
diff --git a/src/runner.c b/src/runner.c
index ade14ee625136c9ed2b6bc22ac1e0f539e320bf9..3056690cdde26cadc67f7b4ee83f4624ebccb4e0 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -729,9 +729,9 @@ void runner_dodrift(struct runner *r, struct cell *c, int timer) {
       p->x[2] += xp->v_full[2] * dt;
 
       /* Predict velocities (for hydro terms) */
-      p->v[0] += p->a[0] * dt;
-      p->v[1] += p->a[1] * dt;
-      p->v[2] += p->a[2] * dt;
+      p->v[0] += p->a_hydro[0] * dt;
+      p->v[1] += p->a_hydro[1] * dt;
+      p->v[2] += p->a_hydro[2] * dt;
 
       /* Predict smoothing length */
       w = p->force.h_dt * h_inv * dt;
@@ -901,13 +901,13 @@ void runner_dokick(struct runner *r, struct cell *c, int timer) {
         p->t_end = p->t_begin + new_dt;
 
         /* Kick particles in momentum space */
-        xp->v_full[0] += p->a[0] * dt;
-        xp->v_full[1] += p->a[1] * dt;
-        xp->v_full[2] += p->a[2] * dt;
+        xp->v_full[0] += p->a_hydro[0] * dt;
+        xp->v_full[1] += p->a_hydro[1] * dt;
+        xp->v_full[2] += p->a_hydro[2] * dt;
 
-        p->v[0] = xp->v_full[0] - half_dt * p->a[0];
-        p->v[1] = xp->v_full[1] - half_dt * p->a[1];
-        p->v[2] = xp->v_full[2] - half_dt * p->a[2];
+        p->v[0] = xp->v_full[0] - half_dt * p->a_hydro[0];
+        p->v[1] = xp->v_full[1] - half_dt * p->a_hydro[1];
+        p->v[2] = xp->v_full[2] - half_dt * p->a_hydro[2];
 
         /* if(p->id == 1000 || p->id == 515050 || p->id == 504849) */
         /*   message("%lld: current_t=%f t_beg=%f t_end=%f half_dt=%f v=[%.3e
diff --git a/src/tools.c b/src/tools.c
index 34cd4c436a128a3e177a7d4405b313130b143889..4fd704a7ff53c6579d51883e6e7b51dc6b156b62 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -420,7 +420,7 @@ void engine_single_force(double *dim, long long int pid,
   }
 
   /* Dump the result. */
-  message("part %lli (h=%e) has a=[%.3e,%.3e,%.3e]", p.id, p.h, p.a[0], p.a[1],
-          p.a[2]);
+  message("part %lli (h=%e) has a=[%.3e,%.3e,%.3e]", p.id, p.h, p.a_hydro[0], p.a_hydro[1],
+          p.a_hydro[2]);
   fflush(stdout);
 }