diff --git a/mongoose.c b/mongoose.c
index e2595a91..fc746ae6 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -3706,14 +3706,6 @@ void mg_timer_poll(unsigned long now_ms) {
 #include <mbedtls/debug.h>
 #include <mbedtls/ssl.h>
 
-#ifndef EXTERN_C
-#ifdef __cplusplus
-#define EXTERN_C extern "C"
-#else
-#define EXTERN_C
-#endif
-#endif
-
 #if defined(MBEDTLS_VERSION_NUMBER) && MBEDTLS_VERSION_NUMBER >= 0x03000000
 #define RNG , rng_get, NULL
 #else
@@ -3779,9 +3771,9 @@ void mg_tls_init(struct mg_connection *c, struct mg_tls_opts *opts) {
   const char *ca = opts->ca == NULL     ? "-"
                    : opts->ca[0] == '-' ? "(emb)"
                                         : opts->ca;
-  const char *crl = opts->crl == NULL    ? "-"
-                   : opts->crl[0] == '-' ? "(emb)"
-                                         : opts->crl;
+  const char *crl = opts->crl == NULL     ? "-"
+                    : opts->crl[0] == '-' ? "(emb)"
+                                          : opts->crl;
   const char *cert = opts->cert == NULL     ? "-"
                      : opts->cert[0] == '-' ? "(emb)"
                                             : opts->cert;
diff --git a/mongoose.h b/mongoose.h
index b47df848..6044fce1 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -609,6 +609,14 @@ void mg_usleep(unsigned long usecs);
 #define mg_htons(x) mg_ntohs(x)
 #define mg_htonl(x) mg_ntohl(x)
 
+#ifndef EXTERN_C
+#ifdef __cplusplus
+#define EXTERN_C extern "C"
+#else
+#define EXTERN_C
+#endif
+#endif
+
 // Expands to a string representation of its argument: e.g.
 // MG_STRINGIFY_LITERAL(5) expands to "5"
 #if !defined(_MSC_VER) || _MSC_VER >= 1900
diff --git a/src/tls.c b/src/tls.c
index cade329e..459077e0 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -8,14 +8,6 @@
 #include <mbedtls/debug.h>
 #include <mbedtls/ssl.h>
 
-#ifndef EXTERN_C
-#ifdef __cplusplus
-#define EXTERN_C extern "C"
-#else
-#define EXTERN_C
-#endif
-#endif
-
 #if defined(MBEDTLS_VERSION_NUMBER) && MBEDTLS_VERSION_NUMBER >= 0x03000000
 #define RNG , rng_get, NULL
 #else
@@ -81,9 +73,9 @@ void mg_tls_init(struct mg_connection *c, struct mg_tls_opts *opts) {
   const char *ca = opts->ca == NULL     ? "-"
                    : opts->ca[0] == '-' ? "(emb)"
                                         : opts->ca;
-  const char *crl = opts->crl == NULL    ? "-"
-                   : opts->crl[0] == '-' ? "(emb)"
-                                         : opts->crl;
+  const char *crl = opts->crl == NULL     ? "-"
+                    : opts->crl[0] == '-' ? "(emb)"
+                                          : opts->crl;
   const char *cert = opts->cert == NULL     ? "-"
                      : opts->cert[0] == '-' ? "(emb)"
                                             : opts->cert;
diff --git a/src/util.h b/src/util.h
index c89bbf68..bcd5dbd4 100644
--- a/src/util.h
+++ b/src/util.h
@@ -27,6 +27,14 @@ void mg_usleep(unsigned long usecs);
 #define mg_htons(x) mg_ntohs(x)
 #define mg_htonl(x) mg_ntohl(x)
 
+#ifndef EXTERN_C
+#ifdef __cplusplus
+#define EXTERN_C extern "C"
+#else
+#define EXTERN_C
+#endif
+#endif
+
 // Expands to a string representation of its argument: e.g.
 // MG_STRINGIFY_LITERAL(5) expands to "5"
 #if !defined(_MSC_VER) || _MSC_VER >= 1900