diff --git a/include/ecrt.h b/include/ecrt.h
index b33f5010..eb99f659 100644
--- a/include/ecrt.h
+++ b/include/ecrt.h
@@ -1866,7 +1866,7 @@ void ecrt_domain_external_memory(
  * \return Pointer to the process data memory.
  */
 EC_PUBLIC_API uint8_t *ecrt_domain_data(
-        ec_domain_t *domain /**< Domain. */
+        const ec_domain_t *domain /**< Domain. */
         );
 
 /** Determines the states of the domain's datagrams.
diff --git a/lib/domain.c b/lib/domain.c
index 26d01262..c04fdeee 100644
--- a/lib/domain.c
+++ b/lib/domain.c
@@ -83,22 +83,8 @@ size_t ecrt_domain_size(const ec_domain_t *domain)
 
 /****************************************************************************/
 
-uint8_t *ecrt_domain_data(ec_domain_t *domain)
+uint8_t *ecrt_domain_data(const ec_domain_t *domain)
 {
-    if (!domain->process_data) {
-        int offset = 0;
-
-        offset = ioctl(domain->master->fd, EC_IOCTL_DOMAIN_OFFSET,
-                domain->index);
-        if (EC_IOCTL_IS_ERROR(offset)) {
-            fprintf(stderr, "Failed to get domain offset: %s\n",
-                    strerror(EC_IOCTL_ERRNO(offset)));
-            return NULL;
-        }
-
-        domain->process_data = domain->master->process_data + offset;
-    }
-
     return domain->process_data;
 }
 
diff --git a/lib/master.c b/lib/master.c
index f2d846e1..a215d3e2 100644
--- a/lib/master.c
+++ b/lib/master.c
@@ -585,6 +585,21 @@ int ecrt_master_activate(ec_master_t *master)
         master->process_data[0] = 0x00;
     }
 
+    // pick up process data pointers for all created domains
+    ec_domain_t *domain = master->first_domain;
+    while (domain) {
+        int offset = ioctl(domain->master->fd, EC_IOCTL_DOMAIN_OFFSET,
+                domain->index);
+        if (EC_IOCTL_IS_ERROR(offset)) {
+            fprintf(stderr, "Failed to get domain offset: %s\n",
+                    strerror(EC_IOCTL_ERRNO(offset)));
+            return -EC_IOCTL_ERRNO(offset);
+        }
+
+        domain->process_data = master->process_data + offset;
+        domain = domain->next;
+    }
+
     return 0;
 }
 
diff --git a/master/domain.c b/master/domain.c
index c61a3c1c..0a886821 100644
--- a/master/domain.c
+++ b/master/domain.c
@@ -440,7 +440,7 @@ void ecrt_domain_external_memory(ec_domain_t *domain, uint8_t *mem)
 
 /****************************************************************************/
 
-uint8_t *ecrt_domain_data(ec_domain_t *domain)
+uint8_t *ecrt_domain_data(const ec_domain_t *domain)
 {
     return domain->data;
 }