diff --git a/cpld.cpp b/cpld.cpp
index 6194278..5345a74 100644
--- a/cpld.cpp
+++ b/cpld.cpp
@@ -51,7 +51,8 @@
 {
     if ((*dataLen) < sizeof(struct CpldRequest))
     {
-        fprintf(stderr, "Invalid command length: %lu\n", (*dataLen));
+        fprintf(stderr, "Invalid command length: %u\n",
+                static_cast<uint32_t>(*dataLen));
         return IPMI_CC_INVALID;
     }