diff --git a/src/dsk.c b/src/dsk.c
index 59983b9..b9d3e79 100644
--- a/src/dsk.c
+++ b/src/dsk.c
@@ -1032,9 +1032,9 @@ LispPTR DSK_getfilename(LispPTR *args)
       len = strlen(lfname);
 
 #ifndef BYTESWAP
-      strncpy(base, lfname, len + 1);
+      strncpy(base, lfname, len);
 #else
-      MemCpyToLispFromNative(base, lfname, len + 1);
+      MemCpyToLispFromNative(base, lfname, len);
 #endif /* BYTESWAP */
 
       return (GetPosSmallp(len));
@@ -1068,9 +1068,9 @@ LispPTR DSK_getfilename(LispPTR *args)
   len = strlen(lfname);
 
 #ifndef BYTESWAP
-  strncpy(base, lfname, len + 1);
+  strncpy(base, lfname, len);
 #else
-  MemCpyToLispFromNative(base, lfname, len + 1);
+  MemCpyToLispFromNative(base, lfname, len);
 #endif /* BYTESWAP */
 
   return (GetPosSmallp(len));
@@ -1507,9 +1507,9 @@ LispPTR DSK_directorynamep(LispPTR *args)
   STRING_BASE(args[1], base);
 
 #ifndef BYTESWAP
-  strncpy(base, dirname, len + 1);
+  strncpy(base, dirname, len);
 #else
-  MemCpyToLispFromNative(base, dirname, len + 1);
+  MemCpyToLispFromNative(base, dirname, len);
 #endif /* BYTESWAP */
 
   return (GetPosSmallp(len));
diff --git a/src/ufs.c b/src/ufs.c
index cb62990..802f5ee 100644
--- a/src/ufs.c
+++ b/src/ufs.c
@@ -216,9 +216,9 @@ LispPTR UFS_getfilename(LispPTR *args)
   len = strlen(lfname);
 
 #ifndef BYTESWAP
-  strncpy(base, lfname, len + 1);
+  strncpy(base, lfname, len);
 #else
-  MemCpyToLispFromNative(base, lfname, len + 1);
+  MemCpyToLispFromNative(base, lfname, len);
 #endif /* BYTESWAP */
 
   return (GetSmallp(len));
@@ -420,9 +420,9 @@ LispPTR UFS_directorynamep(LispPTR *args)
   STRING_BASE(args[1], base);
 
 #ifndef BYTESWAP
-  strncpy(base, dirname, len + 1);
+  strncpy(base, dirname, len);
 #else
-  MemCpyToLispFromNative(base, dirname, len + 1);
+  MemCpyToLispFromNative(base, dirname, len);
 #endif /* BYTESWAP */
 
   return (GetSmallp(len));