diff --git a/src/gui.c b/src/gui.c
index 3291f25..efcb998 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -1640,7 +1640,6 @@ void nwipe_gui_prng( void )
     extern nwipe_prng_t nwipe_twister;
     extern nwipe_prng_t nwipe_isaac;
     extern nwipe_prng_t nwipe_isaac64;
-    extern nwipe_prng_t nwipe_aes_ctr_prng;
     extern nwipe_prng_t nwipe_xoroshiro256_prng;
     extern nwipe_prng_t nwipe_add_lagg_fibonacci_prng;
     extern nwipe_prng_t nwipe_aes_ctr_prng;
@@ -1979,6 +1978,11 @@ void nwipe_gui_prng( void )
                 {
                     nwipe_options.prng = &nwipe_xoroshiro256_prng;
                 }
+                if( focus == 5 )
+                {
+                    nwipe_options.prng = &nwipe_aes_ctr_prng;
+                }
+
                 return;
 
             case KEY_BACKSPACE:
diff --git a/src/options.c b/src/options.c
index 5c7b6f5..e2042de 100644
--- a/src/options.c
+++ b/src/options.c
@@ -39,20 +39,25 @@ nwipe_options_t nwipe_options;
  */
 void cpuid( uint32_t eax, uint32_t* eax_out, uint32_t* ebx_out, uint32_t* ecx_out, uint32_t* edx_out )
 {
-#if defined( _MSC_VER )  // Microsoft compiler
-    int registers[4];
-    __cpuid( registers, eax );
-    *eax_out = registers[0];
-    *ebx_out = registers[1];
-    *ecx_out = registers[2];
-    *edx_out = registers[3];
-#elif defined( __GNUC__ )  // GCC and Clang
+#if defined( __i386__ ) || defined( __x86_64__ ) /* only on x86 */
+#if defined( _MSC_VER ) /* MSVC */
+    int r[4];
+    __cpuid( r, eax );
+    *eax_out = r[0];
+    *ebx_out = r[1];
+    *ecx_out = r[2];
+    *edx_out = r[3];
+#elif defined( __GNUC__ ) /* GCC/Clang */
     __asm__ __volatile__( "cpuid"
                           : "=a"( *eax_out ), "=b"( *ebx_out ), "=c"( *ecx_out ), "=d"( *edx_out )
                           : "a"( eax ) );
 #else
 #error "Unsupported compiler"
 #endif
+#else /* not-x86  */
+    (void) eax;
+    *eax_out = *ebx_out = *ecx_out = *edx_out = 0; /* CPUID = 0  */
+#endif
 }
 
 /*
@@ -61,9 +66,13 @@ void cpuid( uint32_t eax, uint32_t* eax_out, uint32_t* ebx_out, uint32_t* ecx_ou
  */
 int has_aes_ni( void )
 {
+#if defined( __i386__ ) || defined( __x86_64__ ) /* only for x86 */
     uint32_t eax, ebx, ecx, edx;
     cpuid( 1, &eax, &ebx, &ecx, &edx );
-    return ( ecx & ( 1 << 25 ) ) != 0;  // Check if bit 25 in ECX is set
+    return ( ecx & ( 1u << 25 ) ) != 0; /* Bit 25 = AES-NI */
+#else /* ARM, RISC-V … */
+    return 0; /* no AES-NI    */
+#endif
 }
 
 int nwipe_options_parse( int argc, char** argv )