diff --git a/src/common/pico_sync/lock_core.c b/src/common/pico_sync/lock_core.c
index cf53a05..20cc959 100644
--- a/src/common/pico_sync/lock_core.c
+++ b/src/common/pico_sync/lock_core.c
@@ -7,7 +7,7 @@
 #include "pico/lock_core.h"
 
 void lock_init(lock_core_t *core, uint lock_num) {
-    assert(lock_num >= 0 && lock_num < NUM_SPIN_LOCKS);
+    assert(lock_num < NUM_SPIN_LOCKS);
     core->spin_lock = spin_lock_instance(lock_num);
 }
 
diff --git a/src/rp2_common/hardware_sync/sync.c b/src/rp2_common/hardware_sync/sync.c
index dba040a..c032a27 100644
--- a/src/rp2_common/hardware_sync/sync.c
+++ b/src/rp2_common/hardware_sync/sync.c
@@ -22,7 +22,7 @@ void spin_locks_reset(void) {
 }
 
 spin_lock_t *spin_lock_init(uint lock_num) {
-    assert(lock_num >= 0 && lock_num < NUM_SPIN_LOCKS);
+    assert(lock_num < NUM_SPIN_LOCKS);
     spin_lock_t *lock = spin_lock_instance(lock_num);
     spin_unlock_unsafe(lock);
     return lock;