diff --git a/src/hydro/Gadget2/hydro_iact.h b/src/hydro/Gadget2/hydro_iact.h
index b9807b6332e08012d47ad63652377f4fe5337bf9..bec6b004a483e094e8ef299956a28ddfc7007a20 100644
--- a/src/hydro/Gadget2/hydro_iact.h
+++ b/src/hydro/Gadget2/hydro_iact.h
@@ -432,7 +432,7 @@ __attribute__((always_inline)) INLINE static void runner_iact_force(
   const float balsara_j = pj->force.balsara;
 
   /* Are the particles moving towards each others ? */
-  const float omega_ij = fminf(dvdr, 0.f);
+  const float omega_ij = (dvdr < 0.f) ? dvdr: 0.f;
   const float mu_ij = fac_mu * r_inv * omega_ij; /* This is 0 or negative */
 
   /* Signal velocity */
@@ -465,8 +465,8 @@ __attribute__((always_inline)) INLINE static void runner_iact_force(
   pj->force.h_dt -= mi * dvdr * r_inv / rhoi * wj_dr;
 
   /* Update the signal velocity. */
-  pi->force.v_sig = fmaxf(pi->force.v_sig, v_sig);
-  pj->force.v_sig = fmaxf(pj->force.v_sig, v_sig);
+  pi->force.v_sig = (pi->force.v_sig > v_sig) ? pi->force.v_sig : v_sig;
+  pj->force.v_sig = (pj->force.v_sig > v_sig) ? pj->force.v_sig : v_sig;
 
   /* Change in entropy */
   pi->entropy_dt += mj * visc_term * dvdr;
@@ -707,7 +707,7 @@ __attribute__((always_inline)) INLINE static void runner_iact_nonsym_force(
   const float balsara_j = pj->force.balsara;
 
   /* Are the particles moving towards each others ? */
-  const float omega_ij = fminf(dvdr, 0.f);
+  const float omega_ij = (dvdr < 0.f) ? dvdr: 0.f;
   const float mu_ij = fac_mu * r_inv * omega_ij; /* This is 0 or negative */
 
   /* Signal velocity */
@@ -735,7 +735,7 @@ __attribute__((always_inline)) INLINE static void runner_iact_nonsym_force(
   pi->force.h_dt -= mj * dvdr * r_inv / rhoj * wi_dr;
 
   /* Update the signal velocity. */
-  pi->force.v_sig = fmaxf(pi->force.v_sig, v_sig);
+  pi->force.v_sig = (pi->force.v_sig > v_sig) ? pi->force.v_sig : v_sig;
 
   /* Change in entropy */
   pi->entropy_dt += mj * visc_term * dvdr;
diff --git a/src/runner.c b/src/runner.c
index eabc622e8c3aa41b5b06c604a4a540b8cf7c13b9..c9c2ef69f46dba5052a9aba917baef9ecaf519c3 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -487,8 +487,8 @@ void runner_do_ghost(struct runner *r, struct cell *c) {
           h_corr = (target_wcount - p->density.wcount) / p->density.wcount_dh;
 
           /* Truncate to the range [ -p->h/2 , p->h ]. */
-          h_corr = fminf(h_corr, p->h);
-          h_corr = fmaxf(h_corr, -p->h * 0.5f);
+	  h_corr = (h_corr < p->h) ? h_corr : p->h;
+	  h_corr = (h_corr > -0.5f * p->h) ? h_corr : -0.5f * p->h;
         }
 
         /* Did we get the right number density? */
@@ -622,7 +622,7 @@ static void runner_do_drift(struct cell *c, struct engine *e) {
       const float dx2 = gp->x_diff[0] * gp->x_diff[0] +
                         gp->x_diff[1] * gp->x_diff[1] +
                         gp->x_diff[2] * gp->x_diff[2];
-      dx2_max = fmaxf(dx2_max, dx2);
+      dx2_max = (dx2_max  > dx2) ? dx2_max : dx2;
     }
 
     /* Loop over all the particles in the cell (more work for these !) */
@@ -640,10 +640,10 @@ static void runner_do_drift(struct cell *c, struct engine *e) {
       const float dx2 = xp->x_diff[0] * xp->x_diff[0] +
                         xp->x_diff[1] * xp->x_diff[1] +
                         xp->x_diff[2] * xp->x_diff[2];
-      dx2_max = fmaxf(dx2_max, dx2);
+      dx2_max = (dx2_max  > dx2) ? dx2_max : dx2;
 
       /* Maximal smoothing length */
-      h_max = fmaxf(p->h, h_max);
+      h_max = (h_max > p->h) ? h_max : p->h;
 
       /* Now collect quantities for statistics */
 
diff --git a/src/timestep.h b/src/timestep.h
index 569120cf9cf989b633da35529f7693c8f62a1910..582f10a658e0be595a22e1066341de3803afb7fc 100644
--- a/src/timestep.h
+++ b/src/timestep.h
@@ -70,14 +70,15 @@ __attribute__((always_inline)) INLINE static int get_gpart_timestep(
 
   const float new_dt_external = gravity_compute_timestep_external(
       e->external_potential, e->physical_constants, gp);
-  const float new_dt_self =
-      gravity_compute_timestep_self(e->physical_constants, gp);
+  /* const float new_dt_self = */
+  /*     gravity_compute_timestep_self(e->physical_constants, gp); */
+  const float new_dt_self = FLT_MAX;  // MATTHIEU
 
-  float new_dt = fminf(new_dt_external, new_dt_self);
+  float new_dt = (new_dt_external < new_dt_self) ? new_dt_external : new_dt_self;
 
   /* Limit timestep within the allowed range */
-  new_dt = fminf(new_dt, e->dt_max);
-  new_dt = fmaxf(new_dt, e->dt_min);
+  new_dt = (new_dt < e->dt_max) ? new_dt : e->dt_max;
+  new_dt = (new_dt > e->dt_min) ? new_dt : e->dt_min;
 
   /* Convert to integer time */
   const int new_dti =
@@ -110,11 +111,11 @@ __attribute__((always_inline)) INLINE static int get_part_timestep(
     /*     gravity_compute_timestep_self(e->physical_constants, p->gpart); */
     const float new_dt_self = FLT_MAX;  // MATTHIEU
 
-    new_dt_grav = fminf(new_dt_external, new_dt_self);
+    new_dt_grav = (new_dt_external < new_dt_self) ? new_dt_external : new_dt_self;
   }
 
   /* Final time-step is minimum of hydro and gravity */
-  float new_dt = fminf(new_dt_hydro, new_dt_grav);
+  float new_dt = (new_dt_hydro < new_dt_grav) ? new_dt_hydro: new_dt_grav;
 
   /* Limit change in h */
   const float dt_h_change =
@@ -122,11 +123,11 @@ __attribute__((always_inline)) INLINE static int get_part_timestep(
           ? fabsf(e->hydro_properties->log_max_h_change * p->h / p->force.h_dt)
           : FLT_MAX;
 
-  new_dt = fminf(new_dt, dt_h_change);
+  new_dt = (new_dt < dt_h_change) ? new_dt : dt_h_change;
 
   /* Limit timestep within the allowed range */
-  new_dt = fminf(new_dt, e->dt_max);
-  new_dt = fmaxf(new_dt, e->dt_min);
+  new_dt = (new_dt < e->dt_max) ? new_dt : e->dt_max;
+  new_dt = (new_dt > e->dt_min) ? new_dt : e->dt_min;
 
   /* Convert to integer time */
   const int new_dti =