diff --git a/src/libltfs/tape.c b/src/libltfs/tape.c
index 255ca2a2..c4fad3dc 100644
--- a/src/libltfs/tape.c
+++ b/src/libltfs/tape.c
@@ -1783,7 +1783,7 @@ int tape_set_cart_coherency(struct device_data *dev, const tape_partition_t part
 	coh_data[30] = 0;  /* Size of APPLICATION CLIENT SPECIFIC INFORMATION (Byte 1) */
 	coh_data[31] = 43; /* Size of APPLICATION CLIENT SPECIFIC INFORMATION (Byte 0) */
 	/* Size of the buffer to insert 'LTFS' needs to be size of 5 for the 4 letters and the null terminator*/
-	arch_strncpy((char *)coh_data + 32,"LTFS", 5, 4);
+	arch_strncpy((char *)coh_data + 32,"LTFS", 5, 5);
 	memcpy(coh_data + 37, coh->uuid, 37);
 	/*
 	   Version field