diff --git a/archival/libarchive/lzo1x_d.c b/archival/libarchive/lzo1x_d.c
index 40b167e68..43cf4a04e 100644
--- a/archival/libarchive/lzo1x_d.c
+++ b/archival/libarchive/lzo1x_d.c
@@ -31,8 +31,7 @@
 ************************************************************************/
 /* safe decompression with overrun testing */
 int lzo1x_decompress_safe(const uint8_t* in, unsigned in_len,
-		uint8_t* out, unsigned* out_len,
-		void* wrkmem UNUSED_PARAM)
+		uint8_t* out, unsigned* out_len /*, void* wrkmem */)
 {
 	register uint8_t* op;
 	register const uint8_t* ip;
diff --git a/archival/lzop.c b/archival/lzop.c
index da09b7a82..ba27aeff0 100644
--- a/archival/lzop.c
+++ b/archival/lzop.c
@@ -141,8 +141,7 @@ static void copy3(uint8_t* ip, const uint8_t* m_pos, unsigned off)
 #define TEST_OP		(op <= op_end)
 
 static NOINLINE int lzo1x_optimize(uint8_t *in, unsigned in_len,
-		uint8_t *out, unsigned *out_len,
-		void* wrkmem UNUSED_PARAM)
+		uint8_t *out, unsigned *out_len /*, void* wrkmem */)
 {
 	uint8_t* op;
 	uint8_t* ip;
@@ -724,7 +723,7 @@ static NOINLINE int lzo_compress(const header_t *h)
 			/* optimize */
 			if (h->method == M_LZO1X_999) {
 				unsigned new_len = src_len;
-				r = lzo1x_optimize(b2, dst_len, b1, &new_len, NULL);
+				r = lzo1x_optimize(b2, dst_len, b1, &new_len /*, NULL*/);
 				if (r != 0 /*LZO_E_OK*/ || new_len != src_len)
 					bb_error_msg_and_die("internal error - optimization failed");
 			}
@@ -859,9 +858,9 @@ static NOINLINE int lzo_decompress(const header_t *h)
 
 			/* decompress */
 //			if (option_mask32 & OPT_F)
-//				r = lzo1x_decompress(b1, src_len, b2, &d, NULL);
+//				r = lzo1x_decompress(b1, src_len, b2, &d /*, NULL*/);
 //			else
-				r = lzo1x_decompress_safe(b1, src_len, b2, &d, NULL);
+				r = lzo1x_decompress_safe(b1, src_len, b2, &d /*, NULL*/);
 
 			if (r != 0 /*LZO_E_OK*/ || dst_len != d) {
 				bb_error_msg_and_die("corrupted data");
diff --git a/include/liblzo_interface.h b/include/liblzo_interface.h
index b7f1b639b..1e194b944 100644
--- a/include/liblzo_interface.h
+++ b/include/liblzo_interface.h
@@ -49,12 +49,10 @@ int lzo1x_999_compress_level(const uint8_t* in, unsigned in_len,
 
 /* decompression */
 //int lzo1x_decompress(const uint8_t* src, unsigned src_len,
-//		uint8_t* dst, unsigned* dst_len,
-//		void* wrkmem /* NOT USED */);
+//		uint8_t* dst, unsigned* dst_len /*, void* wrkmem */);
 /* safe decompression with overrun testing */
 int lzo1x_decompress_safe(const uint8_t* src, unsigned src_len,
-		uint8_t* dst, unsigned* dst_len,
-		void* wrkmem /* NOT USED */);
+		uint8_t* dst, unsigned* dst_len	/*, void* wrkmem */);
 
 #define LZO_E_OK                    0
 #define LZO_E_ERROR                 (-1)