diff --git a/otp.c b/otp.c
index 87c3b0c..472cb0a 100644
--- a/otp.c
+++ b/otp.c
@@ -75,8 +75,8 @@ hotp(enum otp_hmac hmac, const void *key, size_t key_len, uint64_t counter,
 }
 
 int32_t
-totp(enum otp_hmac hmac, const void *key, size_t key_len, time_t t,
-    unsigned int granularity, unsigned int digits)
+totp(enum otp_hmac hmac, const void *key, size_t key_len, uint64_t t,
+    unsigned int step, unsigned int digits)
 {
 	return -1;
 }
diff --git a/otp.h b/otp.h
index 812009e..adaccd5 100644
--- a/otp.h
+++ b/otp.h
@@ -14,7 +14,6 @@
  */
 
 #include <stdint.h>
-#include <time.h>
 
 enum otp_hmac {
 	OTP_HMAC_SHA1,
@@ -23,5 +22,5 @@ enum otp_hmac {
 };
 
 int32_t hotp(enum otp_hmac, const void *, size_t, uint64_t, unsigned int);
-int32_t totp(enum otp_hmac, const void *, size_t, time_t, unsigned int,
+int32_t totp(enum otp_hmac, const void *, size_t, uint64_t, unsigned int,
     unsigned int);