diff --git a/include/auth.h b/include/auth.h
index 0376d3f..d4d65d4 100644
--- a/include/auth.h
+++ b/include/auth.h
@@ -17,13 +17,15 @@
  */
 
 
-#include "n2n.h"
-
-
 #ifndef AUTH_H
 #define AUTH_H
 
 
+#include <stddef.h>  // for size_t
+#include <stdint.h>  // for uint8_t, uint32_t
+#include "n2n.h"     // for n2n_private_public_key_t, n2n_community_t, N2N_A...
+
+
 int bin_to_ascii (char *out, uint8_t *in, size_t in_len);
 
 int ascii_to_bin (uint8_t *out, char *in);
diff --git a/include/n2n.h b/include/n2n.h
index c798722..0d0f860 100644
--- a/include/n2n.h
+++ b/include/n2n.h
@@ -149,7 +149,6 @@
 #include "n2n_regex.h"
 #include "sn_selection.h"
 #include "network_traffic_filter.h"
-#include "auth.h"
 
 #include "n2n_port_mapping.h"
 
diff --git a/src/auth.c b/src/auth.c
index c4422a2..b2d76cf 100644
--- a/src/auth.c
+++ b/src/auth.c
@@ -18,6 +18,11 @@
 
 
 #include "auth.h"
+#include <stdlib.h>      // for calloc, free
+#include <string.h>      // for strlen, size_t
+#include "curve25519.h"  // for curve25519
+#include "pearson.h"     // for pearson_hash_128, pearson_hash_256
+#include "speck.h"       // for speck_context_t, speck_128_encrypt, speck_init
 
 
 // mapping six binary bits to printable ascii character
diff --git a/src/edge.c b/src/edge.c
index 33040a3..c626004 100644
--- a/src/edge.c
+++ b/src/edge.c
@@ -16,6 +16,7 @@
  *
  */
 
+#include "auth.h"                    // for generate_private_key, generate_p...
 #include "n2n.h"
 
 /* *************************************************** */
diff --git a/src/edge_utils.c b/src/edge_utils.c
index 378376d..81b5e3a 100644
--- a/src/edge_utils.c
+++ b/src/edge_utils.c
@@ -16,6 +16,7 @@
  *
  */
 
+#include "auth.h"                    // for generate_private_key
 #include "n2n.h"
 #include "network_traffic_filter.h"
 #include "edge_utils_win32.h"
diff --git a/src/sn_utils.c b/src/sn_utils.c
index 16b9d64..ed90b9e 100644
--- a/src/sn_utils.c
+++ b/src/sn_utils.c
@@ -16,6 +16,7 @@
  *
  */
 
+#include "auth.h"               // for ascii_to_bin, calculate_dynamic_key
 #include "n2n.h"
 
 #define HASH_FIND_COMMUNITY(head, name, out) HASH_FIND_STR(head, name, out)
diff --git a/tools/n2n-keygen.c b/tools/n2n-keygen.c
index 3ce25f9..a734464 100644
--- a/tools/n2n-keygen.c
+++ b/tools/n2n-keygen.c
@@ -17,6 +17,7 @@
  */
 
 
+#include "auth.h"    // for bin_to_ascii, bind_private_key_to_username, gene...
 #include "n2n.h"
 
 
diff --git a/tools/tests-auth.c b/tools/tests-auth.c
index 232df6e..05f0b46 100644
--- a/tools/tests-auth.c
+++ b/tools/tests-auth.c
@@ -18,6 +18,7 @@
 
 #include <inttypes.h>
 
+#include "auth.h"     // for ascii_to_bin, bin_to_ascii, generate_private_key
 #include "n2n.h"
 #include "hexdump.h"