diff --git a/src/liblsquic/lsquic_hpack_dec.c b/src/liblsquic/lsquic_hpack_dec.c
index 43e56a3..af1ee9a 100644
--- a/src/liblsquic/lsquic_hpack_dec.c
+++ b/src/liblsquic/lsquic_hpack_dec.c
@@ -65,7 +65,10 @@ lsquic_hdec_cleanup (struct lsquic_hdec *dec)
 
 
 //https://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-5.1
-int
+#ifdef NDEBUG
+static
+#endif
+       int
 lsquic_hdec_dec_int (const unsigned char **src, const unsigned char *src_end,
                                         uint8_t prefix_bits, uint32_t *value)
 {
@@ -185,7 +188,10 @@ hdec_huff_decode (const unsigned char *src, int src_len,
 
 
 //reutrn the length in the dst, also update the src
-static int
+#ifdef NDEBUG
+static
+#endif
+       int
 hdec_dec_str (unsigned char *dst, size_t dst_len, const unsigned char **src,
         const unsigned char *src_end)
 {
@@ -244,7 +250,10 @@ hdec_get_table_entry (struct lsquic_hdec *dec, uint32_t index)
 }
 
 
-int
+#ifdef NDEBUG
+static
+#endif
+       int
 lsquic_hdec_push_entry (struct lsquic_hdec *dec, const char *name,
                         uint16_t name_len, const char *val, uint16_t val_len)
 {
diff --git a/src/liblsquic/lsquic_hpack_dec.h b/src/liblsquic/lsquic_hpack_dec.h
index d95b1da..43596a8 100644
--- a/src/liblsquic/lsquic_hpack_dec.h
+++ b/src/liblsquic/lsquic_hpack_dec.h
@@ -45,13 +45,14 @@ lsquic_hdec_set_max_capacity (struct lsquic_hdec *, unsigned);
 size_t
 lsquic_hdec_mem_used (const struct lsquic_hdec *);
 
+#ifndef NDEBUG
 int
 lsquic_hdec_dec_int (const unsigned char **src, const unsigned char *src_end,
                                         uint8_t prefix_bits, uint32_t *value);
-
 int
 lsquic_hdec_push_entry (struct lsquic_hdec *dec, const char *name,
                         hpack_strlen_t name_len, const char *val,
                         hpack_strlen_t val_len);
+#endif
 
 #endif
diff --git a/src/liblsquic/lsquic_hpack_enc.c b/src/liblsquic/lsquic_hpack_enc.c
index 39c003b..bc7ad58 100644
--- a/src/liblsquic/lsquic_hpack_enc.c
+++ b/src/liblsquic/lsquic_hpack_enc.c
@@ -92,7 +92,10 @@ lsquic_henc_cleanup (struct lsquic_henc *enc)
 
 
 //not find return 0, otherwise return the index
-unsigned
+#ifdef NDEBUG
+static
+#endif
+       unsigned
 lsquic_henc_get_stx_tab_id (const char *name, hpack_strlen_t name_len,
                     const char *val, hpack_strlen_t val_len, int *val_matched)
 {
@@ -516,7 +519,10 @@ henc_enc_int (unsigned char *dst, unsigned char *const end, uint32_t value,
 }
 
 
-static int
+#ifdef NDEBUG
+static 
+#endif
+       int
 henc_huffman_enc (const unsigned char *src, const unsigned char *const src_end,
                                             unsigned char *dst, int dst_len)
 {
@@ -556,7 +562,10 @@ henc_huffman_enc (const unsigned char *src, const unsigned char *const src_end,
 }
 
 
-int
+#ifdef NDEBUG
+static
+#endif
+       int
 lsquic_henc_enc_str (unsigned char *const dst, size_t dst_len,
                             const unsigned char *str, hpack_strlen_t str_len)
 {
@@ -702,7 +711,10 @@ henc_grow_tables (struct lsquic_henc *enc)
     return 0;
 }
 
-int
+#ifdef NDEBUG
+static
+#endif
+       int
 lsquic_henc_push_entry (struct lsquic_henc *enc, const char *name,
                         hpack_strlen_t name_len, const char *value,
                         hpack_strlen_t value_len)
@@ -819,7 +831,7 @@ lsquic_henc_set_max_capacity (struct lsquic_henc *enc, unsigned max_capacity)
     henc_remove_overflow_entries(enc);
 }
 
-
+#ifndef NDEBUG
 void
 lsquic_henc_iter_reset (struct lsquic_henc *enc)
 {
@@ -847,7 +859,7 @@ lsquic_henc_iter_next (struct lsquic_henc *enc,
     retval->entry_id = henc_calc_table_id(enc, entry);
     return 0;
 }
-
+#endif
 
 size_t
 lsquic_henc_mem_used (const struct lsquic_henc *enc)
diff --git a/src/liblsquic/lsquic_hpack_enc.h b/src/liblsquic/lsquic_hpack_enc.h
index 28babd0..14ca6cb 100644
--- a/src/liblsquic/lsquic_hpack_enc.h
+++ b/src/liblsquic/lsquic_hpack_enc.h
@@ -10,6 +10,7 @@
 
 struct enc_table_entry;
 
+#ifndef NDEBUG
 struct enc_dyn_table_entry
 {
     const char *name,       /* Not NUL-terminated */
@@ -18,6 +19,7 @@ struct enc_dyn_table_entry
                 value_len;
     unsigned    entry_id;
 };
+#endif
 
 STAILQ_HEAD(enc_head, enc_table_entry);
 struct double_enc_head;
@@ -42,8 +44,10 @@ struct lsquic_henc
     struct enc_head     hpe_all_entries;
     struct double_enc_head
                        *hpe_buckets;
+#ifndef NDEBUG                       
     const struct enc_table_entry
                        *hpe_iter;
+#endif                       
 };
 
 
@@ -79,6 +83,7 @@ lsquic_henc_set_max_capacity (struct lsquic_henc *, unsigned);
 size_t
 lsquic_henc_mem_used (const struct lsquic_henc *);
 
+#ifndef NDEBUG
 unsigned
 lsquic_henc_get_stx_tab_id (const char *name, hpack_strlen_t name_len,
                     const char *val, hpack_strlen_t val_len, int *val_matched);
@@ -97,5 +102,6 @@ lsquic_henc_iter_reset (struct lsquic_henc *enc);
 /* Returns 0 if entry is found */
 int
 lsquic_henc_iter_next (struct lsquic_henc *enc, struct enc_dyn_table_entry *);
+#endif
 
 #endif
diff --git a/src/liblsquic/lsquic_parse.h b/src/liblsquic/lsquic_parse.h
index 1f8fb13..6d220a0 100644
--- a/src/liblsquic/lsquic_parse.h
+++ b/src/liblsquic/lsquic_parse.h
@@ -143,6 +143,7 @@ struct parse_funcs
                 uint16_t *reason_length, const char **reason);
     int
     (*pf_gen_ping_frame) (unsigned char *buf, int buf_len);
+#ifndef NDEBUG    
     /* These float reading and writing functions assume `mem' has at least
      * 2 bytes.
      */
@@ -150,6 +151,7 @@ struct parse_funcs
     (*pf_write_float_time16) (lsquic_time_t time_us, void *mem);
     uint64_t
     (*pf_read_float_time16) (const void *mem);
+#endif    
     size_t
     (*pf_calc_stream_frame_header_sz) (uint32_t stream_id, uint64_t offset);
     void