diff --git a/ext4_utils/wipe.c b/ext4_utils/wipe.c
index 990b82f..c7329cf 100644
--- a/ext4_utils/wipe.c
+++ b/ext4_utils/wipe.c
@@ -30,7 +30,7 @@
 #define BLKSECDISCARD _IO(0x12,125)
 #endif
 
-int wipe_block_device(int fd, int len)
+int wipe_block_device(int fd, s64 len)
 {
 	u64 range[2];
 	int ret;
@@ -54,7 +54,7 @@
 	return 0;
 }
 #else
-int wipe_block_device(int fd, int len)
+int wipe_block_device(int fd, s64 len)
 {
 	error("wipe not supported on non-linux platforms");
 	return 1;
diff --git a/ext4_utils/wipe.h b/ext4_utils/wipe.h
index 0b54b46..814877d 100644
--- a/ext4_utils/wipe.h
+++ b/ext4_utils/wipe.h
@@ -17,6 +17,6 @@
 #ifndef _WIPE_H_
 #define _WIPE_H_
 
-int wipe_block_device(int fd, int len);
+int wipe_block_device(int fd, s64 len);
 
 #endif