diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h
index 1d0ed81138..2244a87823 100644
--- a/src/shared/tpm2-util.h
+++ b/src/shared/tpm2-util.h
@@ -40,7 +40,9 @@ typedef enum TPM2Flags {
 static inline bool TPM2_PCR_INDEX_VALID(unsigned pcr) {
         return pcr < TPM2_PCRS_MAX;
 }
-static inline bool TPM2_PCR_MASK_VALID(uint32_t pcr_mask) {
+
+/* Some fields like `pcr_mask` field of `struct tpm2_credential_header` are 64-bit. */
+static inline bool TPM2_PCR_MASK_VALID(uint64_t pcr_mask) {
         return pcr_mask <= TPM2_PCRS_MASK;
 }