diff --git a/src/main/fc/fc_msp.c b/src/main/fc/fc_msp.c
index 6bebe242ea..4b35329c14 100644
--- a/src/main/fc/fc_msp.c
+++ b/src/main/fc/fc_msp.c
@@ -1069,7 +1069,7 @@ static bool mspFcProcessOutCommand(uint8_t cmdMSP, sbuf_t *dst)
         sbufWriteU8(dst, blackboxConfig()->device);
         sbufWriteU8(dst, blackboxGetRateNum());
         sbufWriteU8(dst, blackboxGetRateDenom());
-        sbufWriteU8(dst, blackboxConfig()->p_denom);
+        sbufWriteU16(dst, blackboxConfig()->p_denom);
 #else
         sbufWriteU8(dst, 0); // Blackbox not supported
         sbufWriteU8(dst, 0);
@@ -1609,7 +1609,7 @@ static mspResult_e mspFcProcessInCommand(uint8_t cmdMSP, sbuf_t *src)
             const int rateDenom = sbufReadU8(src); // was rate_denom
             if (sbufBytesRemaining(src) >= 1) {
                 // p_denom specified, so use it directly
-                blackboxConfigMutable()->p_denom = sbufReadU8(src);
+                blackboxConfigMutable()->p_denom = sbufReadU16(src);
             } else {
                 // p_denom not specified in MSP, so calculate it from old rateNum and rateDenom
                 blackboxConfigMutable()->p_denom = blackboxCalculatePDenom(rateNum, rateDenom);