diff --git a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio
index 5244bd0e..5ecfed80 100644
--- a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio
+++ b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio
@@ -8,8 +8,8 @@
     mov rxfifo3, isr
 
     mov osr, rxfifoy
-;    mov osr, rxfifo0
-;    mov osr, rxfifo1
-;    mov osr, rxfifo2
-;    mov osr, rxfifo3
+    mov osr, rxfifo0
+    mov osr, rxfifo1
+    mov osr, rxfifo2
+    mov osr, rxfifo3
 .wrap
diff --git a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio.h b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio.h
index 92ea7e16..09f9ca44 100644
--- a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio.h
+++ b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/comparison_tests/movrx.pio.h
@@ -9,8 +9,8 @@ static const uint16_t movrx_program_instructions[] = {
     0x8013, // mov rxfifo3, isr
     // 0b1000_ssss_1001_yiii
     0x8098, // mov osr, rxfifoy
-            // 0x8090, // mov osr, rxfifo0
-            // 0x8091, // mov osr, rxfifo1
-            // 0x8092, // mov osr, rxfifo2
-            // 0x8093, // mov osr, rxfifo3
+    0x8090, // mov osr, rxfifo0
+    0x8091, // mov osr, rxfifo1
+    0x8092, // mov osr, rxfifo2
+    0x8093, // mov osr, rxfifo3
 };
diff --git a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/tokenizer.zig b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/tokenizer.zig
index fc4e7db0..d53a24e3 100644
--- a/port/raspberrypi/rp2xxx/src/hal/pio/assembler/tokenizer.zig
+++ b/port/raspberrypi/rp2xxx/src/hal/pio/assembler/tokenizer.zig
@@ -874,6 +874,7 @@ pub fn Tokenizer(chip: Chip) type {
                         if (value > 3) {
                             return error.InvalidSource;
                         }
+                        idx = @intCast(value);
                     }
                 } else {
                     diags.* = Diagnostics.init(