diff --git a/libsharp/sharp.c b/libsharp/sharp.c
index 913b5de..1daeb7a 100644
--- a/libsharp/sharp.c
+++ b/libsharp/sharp.c
@@ -427,7 +427,12 @@ static void init_output (sharp_job *job)
   }
 
 static void alloc_phase (sharp_job *job, int nm, int ntheta)
-  { job->phase=RALLOC(dcmplx,2*job->ntrans*job->nmaps*nm*ntheta); }
+  {
+  if ((nm&1023)==0) nm+=3; // hack to avoid critical strides
+  job->s_m=2*job->ntrans*job->nmaps;
+  job->s_th=job->s_m*nm;
+  job->phase=RALLOC(dcmplx,2*job->ntrans*job->nmaps*nm*ntheta);
+  }
 
 static void dealloc_phase (sharp_job *job)
   { DEALLOC(job->phase); }
@@ -436,7 +441,7 @@ static void dealloc_phase (sharp_job *job)
 static void map2phase (sharp_job *job, int mmax, int llim, int ulim)
   {
   if (job->type != SHARP_MAP2ALM) return;
-  int pstride = 2*job->ntrans*job->nmaps;
+  int pstride = job->s_m;
 #pragma omp parallel
 {
   ringhelper helper;
@@ -444,7 +449,7 @@ static void map2phase (sharp_job *job, int mmax, int llim, int ulim)
 #pragma omp for schedule(dynamic,1)
   for (int ith=llim; ith<ulim; ++ith)
     {
-    int dim2 = pstride*(ith-llim)*(mmax+1);
+    int dim2 = job->s_th*(ith-llim);
     for (int i=0; i<job->ntrans*job->nmaps; ++i)
       ringhelper_pair2phase(&helper,mmax,&job->ginfo->pair[ith], job->map[i],
         &job->phase[dim2+2*i], &job->phase[dim2+2*i+1], pstride, job->flags);
@@ -589,7 +594,7 @@ static void almtmp2alm (sharp_job *job, int lmax, int mi)
 static void phase2map (sharp_job *job, int mmax, int llim, int ulim)
   {
   if (job->type == SHARP_MAP2ALM) return;
-  int pstride = 2*job->ntrans*job->nmaps;
+  int pstride = job->s_m;
 #pragma omp parallel
 {
   ringhelper helper;
@@ -597,7 +602,7 @@ static void phase2map (sharp_job *job, int mmax, int llim, int ulim)
 #pragma omp for schedule(dynamic,1)
   for (int ith=llim; ith<ulim; ++ith)
     {
-    int dim2 = pstride*(ith-llim)*(mmax+1);
+    int dim2 = job->s_th*(ith-llim);
     for (int i=0; i<job->ntrans*job->nmaps; ++i)
       ringhelper_phase2pair(&helper,mmax,&job->phase[dim2+2*i],
         &job->phase[dim2+2*i+1],pstride,&job->ginfo->pair[ith],job->map[i],
diff --git a/libsharp/sharp_core_inc2.c b/libsharp/sharp_core_inc2.c
index baa2186..a11c488 100644
--- a/libsharp/sharp_core_inc2.c
+++ b/libsharp/sharp_core_inc2.c
@@ -653,7 +653,7 @@ static void Z(inner_loop) (sharp_job *job, const int *ispair,
               {
               for (int j=0; j<njobs; ++j)
                 {
-                int phas_idx = 2*(j+njobs*(itot*job->ainfo->nm+mi));
+                int phas_idx = itot*job->s_th + mi*job->s_m + 2*j;
                 complex double r1 = p1[j].s.r[i] + p1[j].s.i[i]*_Complex_I,
                                r2 = p2[j].s.r[i] + p2[j].s.i[i]*_Complex_I;
                 job->phase[phas_idx] = r1+r2;
@@ -693,7 +693,7 @@ static void Z(inner_loop) (sharp_job *job, const int *ispair,
               {
               for (int j=0; j<njobs; ++j)
                 {
-                int phas_idx = 4*(j+njobs*(itot*job->ainfo->nm+mi));
+                int phas_idx = itot*job->s_th + mi*job->s_m + 4*j;
                 complex double q1 = p1[j].s.qr[i] + p1[j].s.qi[i]*_Complex_I,
                                q2 = p2[j].s.qr[i] + p2[j].s.qi[i]*_Complex_I,
                                u1 = p1[j].s.ur[i] + p1[j].s.ui[i]*_Complex_I,
@@ -736,7 +736,7 @@ static void Z(inner_loop) (sharp_job *job, const int *ispair,
               {
               for (int j=0; j<njobs; ++j)
                 {
-                int phas_idx = 2*(j+njobs*(itot*job->ainfo->nm+mi));
+                int phas_idx = itot*job->s_th + mi*job->s_m + 2*j;
                 dcmplx ph1=job->phase[phas_idx];
                 dcmplx ph2=ispair[itot] ? job->phase[phas_idx+1] : 0.;
                 p1[j].s.r[i]=creal(ph1+ph2); p1[j].s.i[i]=cimag(ph1+ph2);
@@ -766,7 +766,7 @@ static void Z(inner_loop) (sharp_job *job, const int *ispair,
               {
               for (int j=0; j<njobs; ++j)
                 {
-                int phas_idx = 4*(j+njobs*(itot*job->ainfo->nm+mi));
+                int phas_idx = itot*job->s_th + mi*job->s_m + 4*j;
                 dcmplx p1Q=job->phase[phas_idx],
                        p1U=job->phase[phas_idx+2],
                        p2Q=ispair[itot] ? job->phase[phas_idx+1]:0.,
diff --git a/libsharp/sharp_internal.h b/libsharp/sharp_internal.h
index 4fd582d..4ae7ee2 100644
--- a/libsharp/sharp_internal.h
+++ b/libsharp/sharp_internal.h
@@ -48,6 +48,7 @@ typedef struct
   int flags;
   void **map;
   void **alm;
+  int s_m, s_th; // strides in m and theta direction
   complex double *phase;
   double *norm_l;
   complex double *almtmp;