diff --git a/arch/riscv/include/arch/spinlock.h b/arch/riscv/include/arch/spinlock.h
index a73b79e79..22ed69049 100644
--- a/arch/riscv/include/arch/spinlock.h
+++ b/arch/riscv/include/arch/spinlock.h
@@ -15,7 +15,7 @@ __BEGIN_CDECLS
 
 #define SPIN_LOCK_INITIAL_VALUE (0)
 
-typedef volatile unsigned int spin_lock_t;
+typedef volatile uint32_t spin_lock_t;
 
 typedef unsigned long spin_lock_saved_state_t;
 typedef unsigned int spin_lock_save_flags_t;
diff --git a/arch/riscv/spinlock.c b/arch/riscv/spinlock.c
index 441f5fdc7..c12f8c3eb 100644
--- a/arch/riscv/spinlock.c
+++ b/arch/riscv/spinlock.c
@@ -7,17 +7,19 @@
  */
 #include <arch/spinlock.h>
 
+#include <stdint.h>
+
 // super simple spin lock implementation
 
 int riscv_spin_trylock(spin_lock_t *lock) {
-    unsigned long val = arch_curr_cpu_num() + 1UL;
+    // use a full 32/64 type since amoswap overwrites the entire register
     unsigned long old;
 
     __asm__ __volatile__(
         "amoswap.w  %0, %2, %1\n"
         "fence      r, rw\n"
         : "=r"(old), "+A"(*lock)
-        : "r" (val)
+        : "r" (1u)
         : "memory"
     );
 
@@ -25,19 +27,19 @@ int riscv_spin_trylock(spin_lock_t *lock) {
 }
 
 void riscv_spin_lock(spin_lock_t *lock) {
-    unsigned long val = arch_curr_cpu_num() + 1UL;
-
     for (;;) {
         if (*lock) {
+            // TODO: use a yield instruction here?
             continue;
         }
 
+        // use a full 32/64 type since amoswap overwrites the entire register
         unsigned long old;
         __asm__ __volatile__(
             "amoswap.w  %0, %2, %1\n"
             "fence      r, rw\n"
             : "=r"(old), "+A"(*lock)
-            : "r" (val)
+            : "r" (1u)
             : "memory"
         );