diff --git a/blosc/blosc2.c b/blosc/blosc2.c
index faff94972..1d9e1e337 100644
--- a/blosc/blosc2.c
+++ b/blosc/blosc2.c
@@ -16,6 +16,7 @@
 #include <sys/types.h>
 #include <assert.h>
 #include <math.h>
+#include <pthread.h>
 
 #include "blosc2.h"
 #include "blosc-private.h"
@@ -3055,10 +3056,10 @@ static void t_blosc_do_job(void *ctxt)
   }
   else {
     // Use dynamic schedule via a queue.  Get the next block.
-    pthread_mutex_lock(&context->count_mutex);
+    pthread_spin_lock(&context->count_spin);
     context->thread_nblock++;
     nblock_ = context->thread_nblock;
-    pthread_mutex_unlock(&context->count_mutex);
+    pthread_spin_unlock(&context->count_spin);
     tblock = nblocks;
   }
 
@@ -3119,15 +3120,15 @@ static void t_blosc_do_job(void *ctxt)
     /* Check results for the compressed/decompressed block */
     if (cbytes < 0) {            /* compr/decompr failure */
       /* Set giveup_code error */
-      pthread_mutex_lock(&context->count_mutex);
+      pthread_spin_lock(&context->count_spin);
       context->thread_giveup_code = cbytes;
-      pthread_mutex_unlock(&context->count_mutex);
+      pthread_spin_unlock(&context->count_spin);
       break;
     }
 
     if (compress && !memcpyed) {
       /* Start critical section */
-      pthread_mutex_lock(&context->count_mutex);
+      pthread_spin_lock(&context->count_spin);
       ntdest = context->output_bytes;
       // Note: do not use a typical local dict_training variable here
       // because it is probably cached from previous calls if the number of
@@ -3138,13 +3139,13 @@ static void t_blosc_do_job(void *ctxt)
 
       if ((cbytes == 0) || (ntdest + cbytes > maxbytes)) {
         context->thread_giveup_code = 0;  /* incompressible buf */
-        pthread_mutex_unlock(&context->count_mutex);
+        pthread_spin_unlock(&context->count_spin);
         break;
       }
       context->thread_nblock++;
       nblock_ = context->thread_nblock;
       context->output_bytes += cbytes;
-      pthread_mutex_unlock(&context->count_mutex);
+      pthread_spin_unlock(&context->count_spin);
       /* End of critical section */
 
       /* Copy the compressed buffer to destination */
@@ -3154,22 +3155,22 @@ static void t_blosc_do_job(void *ctxt)
       nblock_++;
     }
     else {
-      pthread_mutex_lock(&context->count_mutex);
+      pthread_spin_lock(&context->count_spin);
       context->thread_nblock++;
       nblock_ = context->thread_nblock;
       context->output_bytes += cbytes;
-      pthread_mutex_unlock(&context->count_mutex);
+      pthread_spin_unlock(&context->count_spin);
     }
 
   } /* closes while (nblock_) */
 
   if (static_schedule) {
-    pthread_mutex_lock(&context->count_mutex);
+    pthread_spin_lock(&context->count_spin);
     context->output_bytes = context->sourcesize;
     if (compress) {
       context->output_bytes += context->header_overhead;
     }
-    pthread_mutex_unlock(&context->count_mutex);
+    pthread_spin_unlock(&context->count_spin);
   }
 
 }
@@ -3208,7 +3209,7 @@ int init_threadpool(blosc2_context *context) {
   int rc2;
 
   /* Initialize mutex and condition variable objects */
-  pthread_mutex_init(&context->count_mutex, NULL);
+  pthread_spin_init(&context->count_spin, PTHREAD_PROCESS_SHARED);
   pthread_mutex_init(&context->delta_mutex, NULL);
   pthread_mutex_init(&context->nchunk_mutex, NULL);
   pthread_cond_init(&context->delta_cv, NULL);
@@ -3613,7 +3614,7 @@ int release_threadpool(blosc2_context *context) {
     }
 
     /* Release mutex and condition variable objects */
-    pthread_mutex_destroy(&context->count_mutex);
+    pthread_spin_destroy(&context->count_spin);
     pthread_mutex_destroy(&context->delta_mutex);
     pthread_mutex_destroy(&context->nchunk_mutex);
     pthread_cond_destroy(&context->delta_cv);
diff --git a/blosc/context.h b/blosc/context.h
index ee16613f0..e8718116c 100644
--- a/blosc/context.h
+++ b/blosc/context.h
@@ -121,7 +121,7 @@ struct blosc2_context_s {
   int16_t end_threads;
   pthread_t *threads;
   struct thread_context *thread_contexts; /* only for user-managed threads */
-  pthread_mutex_t count_mutex;
+  pthread_spinlock_t count_spin;
   pthread_mutex_t nchunk_mutex;
 #ifdef BLOSC_POSIX_BARRIERS
   pthread_barrier_t barr_init;