diff --git a/src/rp2040/main.c b/src/rp2040/main.c
index 97fa5eb8..40869618 100644
--- a/src/rp2040/main.c
+++ b/src/rp2040/main.c
@@ -113,8 +113,8 @@ static void
 pll_setup(pll_hw_t *pll, uint32_t mul, uint32_t postdiv)
 {
     // Setup pll
-    uint32_t refdiv = 1, fbdiv = mul, postdiv2 = 2, postdiv1 = postdiv/postdiv2;
-    if (postdiv1 > 0x07) {
+    uint32_t refdiv = 1, fbdiv = mul, postdiv2 = 1, postdiv1 = postdiv;
+    while (postdiv1 > 0x07) {
         postdiv1 >>= 1;
         postdiv2 <<= 1;
     }