diff --git a/include/zenoh-pico/api/primitives.h b/include/zenoh-pico/api/primitives.h
index 37edbaba2..21709337e 100644
--- a/include/zenoh-pico/api/primitives.h
+++ b/include/zenoh-pico/api/primitives.h
@@ -1669,7 +1669,7 @@ z_sample_kind_t z_sample_kind(const z_loaned_sample_t *sample);
  * Return:
  *   The reliability wrapped as a :c:type:`z_reliability_t`.
  */
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
 z_reliability_t z_sample_reliability(const z_loaned_sample_t *sample);
 #endif
 
diff --git a/include/zenoh-pico/api/types.h b/include/zenoh-pico/api/types.h
index eee565fda..f1f6ae955 100644
--- a/include/zenoh-pico/api/types.h
+++ b/include/zenoh-pico/api/types.h
@@ -236,7 +236,7 @@ typedef struct {
     z_congestion_control_t congestion_control;
     z_priority_t priority;
     bool is_express;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     z_reliability_t reliability;
 #endif
 } z_publisher_options_t;
@@ -318,7 +318,7 @@ typedef struct {
     z_timestamp_t *timestamp;
     bool is_express;
     z_moved_bytes_t *attachment;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     z_reliability_t reliability;
 #endif
 } z_put_options_t;
@@ -338,7 +338,7 @@ typedef struct {
     z_priority_t priority;
     bool is_express;
     z_timestamp_t *timestamp;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     z_reliability_t reliability;
 #endif
 } z_delete_options_t;
diff --git a/include/zenoh-pico/config.h b/include/zenoh-pico/config.h
index 1230a0a4b..eda3441d5 100644
--- a/include/zenoh-pico/config.h
+++ b/include/zenoh-pico/config.h
@@ -21,7 +21,7 @@
 #define Z_BATCH_MULTICAST_SIZE 2048
 #define Z_CONFIG_SOCKET_TIMEOUT 100
 
-#define Z_FEATURE_UNSTABLE_API 0
+/* #undef Z_FEATURE_UNSTABLE_API */
 #define Z_FEATURE_MULTI_THREAD 1
 #define Z_FEATURE_PUBLICATION 1
 #define Z_FEATURE_SUBSCRIPTION 1
diff --git a/include/zenoh-pico/config.h.in b/include/zenoh-pico/config.h.in
index 636fd822d..dba1ab27d 100644
--- a/include/zenoh-pico/config.h.in
+++ b/include/zenoh-pico/config.h.in
@@ -21,7 +21,7 @@
 #define Z_BATCH_MULTICAST_SIZE @BATCH_MULTICAST_SIZE@
 #define Z_CONFIG_SOCKET_TIMEOUT @Z_CONFIG_SOCKET_TIMEOUT@
 
-#define Z_FEATURE_UNSTABLE_API @Z_FEATURE_UNSTABLE_API@
+#cmakedefine Z_FEATURE_UNSTABLE_API
 #define Z_FEATURE_MULTI_THREAD @Z_FEATURE_MULTI_THREAD@
 #define Z_FEATURE_PUBLICATION @Z_FEATURE_PUBLICATION@
 #define Z_FEATURE_SUBSCRIPTION @Z_FEATURE_SUBSCRIPTION@
diff --git a/src/api/api.c b/src/api/api.c
index d20ac38b2..5c652f88a 100644
--- a/src/api/api.c
+++ b/src/api/api.c
@@ -1027,7 +1027,7 @@ z_result_t z_id_to_string(const z_id_t *id, z_owned_string_t *str) {
 
 const z_loaned_keyexpr_t *z_sample_keyexpr(const z_loaned_sample_t *sample) { return &sample->keyexpr; }
 z_sample_kind_t z_sample_kind(const z_loaned_sample_t *sample) { return sample->kind; }
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
 z_reliability_t z_sample_reliability(const z_loaned_sample_t *sample) { return sample->reliability; }
 #endif
 const z_loaned_bytes_t *z_sample_payload(const z_loaned_sample_t *sample) { return &sample->payload; }
@@ -1092,7 +1092,7 @@ void z_put_options_default(z_put_options_t *options) {
     options->is_express = false;
     options->timestamp = NULL;
     options->attachment = NULL;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     options->reliability = Z_RELIABILITY_DEFAULT;
 #endif
 }
@@ -1102,7 +1102,7 @@ void z_delete_options_default(z_delete_options_t *options) {
     options->is_express = false;
     options->timestamp = NULL;
     options->priority = Z_PRIORITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     options->reliability = Z_RELIABILITY_DEFAULT;
 #endif
 }
@@ -1117,7 +1117,7 @@ z_result_t z_put(const z_loaned_session_t *zs, const z_loaned_keyexpr_t *keyexpr
         opt = *options;
     }
     z_reliability_t reliability = Z_RELIABILITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     reliability = opt.reliability;
 #endif
 
@@ -1150,7 +1150,7 @@ z_result_t z_delete(const z_loaned_session_t *zs, const z_loaned_keyexpr_t *keye
         opt = *options;
     }
     z_reliability_t reliability = Z_RELIABILITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     reliability = opt.reliability;
 #endif
 
@@ -1165,7 +1165,7 @@ void z_publisher_options_default(z_publisher_options_t *options) {
     options->congestion_control = Z_CONGESTION_CONTROL_DEFAULT;
     options->priority = Z_PRIORITY_DEFAULT;
     options->is_express = false;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     options->reliability = Z_RELIABILITY_DEFAULT;
 #endif
 }
@@ -1193,7 +1193,7 @@ z_result_t z_declare_publisher(z_owned_publisher_t *pub, const z_loaned_session_
         opt = *options;
     }
     z_reliability_t reliability = Z_RELIABILITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     reliability = opt.reliability;
 #endif
 
@@ -1236,7 +1236,7 @@ z_result_t z_publisher_put(const z_loaned_publisher_t *pub, z_moved_bytes_t *pay
         opt = *options;
     }
     z_reliability_t reliability = Z_RELIABILITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     reliability = pub->reliability;
 #endif
 
@@ -1285,7 +1285,7 @@ z_result_t z_publisher_delete(const z_loaned_publisher_t *pub, const z_publisher
         opt = *options;
     }
     z_reliability_t reliability = Z_RELIABILITY_DEFAULT;
-#if Z_FEATURE_UNSTABLE_API == 1
+#ifdef Z_FEATURE_UNSTABLE_API
     reliability = pub->reliability;
 #endif
     // Remove potentially redundant ke suffix