diff --git a/compat.c b/compat.c
index bd3270c8..84510063 100644
--- a/compat.c
+++ b/compat.c
@@ -262,13 +262,14 @@ char *openconnect__win32_strerror(DWORD err)
 	return msgutf8;
 }
 
-void openconnect__win32_sock_init()
+int openconnect__win32_sock_init()
 {
 	WSADATA data;
 	if (WSAStartup (MAKEWORD(1, 1), &data) != 0) {
 		fprintf(stderr, _("ERROR: Cannot initialize sockets\n"));
-		exit(1);
+		return -EIO;
 	}
+	return 0;
 }
 
 int openconnect__win32_inet_pton(int af, const char *src, void *dst)
diff --git a/gnutls.c b/gnutls.c
index d1068357..76ef5b9c 100644
--- a/gnutls.c
+++ b/gnutls.c
@@ -2161,12 +2161,17 @@ void openconnect_close_https(struct openconnect_info *vpninfo, int final)
 	}
 }
 
-void openconnect_init_ssl(void)
+int openconnect_init_ssl(void)
 {
 #ifdef _WIN32
-	openconnect__win32_sock_init();
+	int ret = openconnect__win32_sock_init();
+	if (ret)
+		return ret;
 #endif
-	gnutls_global_init();
+	if (gnutls_global_init())
+		return -EIO;
+	else
+		return 0;
 }
 
 char *get_gnutls_cipher(gnutls_session_t session)
diff --git a/openconnect-internal.h b/openconnect-internal.h
index 065263d5..d2157d6a 100644
--- a/openconnect-internal.h
+++ b/openconnect-internal.h
@@ -526,7 +526,7 @@ static inline int set_fd_cloexec(int fd)
 
 #ifdef _WIN32
 #define pipe(fds) _pipe(fds, 4096, O_BINARY)
-void openconnect__win32_sock_init();
+int openconnect__win32_sock_init();
 char *openconnect__win32_strerror(DWORD err);
 #undef inet_pton
 #define inet_pton openconnect__win32_inet_pton
diff --git a/openconnect.h b/openconnect.h
index a6c6215f..d611103b 100644
--- a/openconnect.h
+++ b/openconnect.h
@@ -35,6 +35,7 @@
  * API version 4.1:
  *  - Add openconnect_get_cstp_cipher(), openconnect_get_dtls_cipher(),
  *    openconnect_set_system_trust().
+ *  - Change openconnect_init_ssl() to return int.
  *
  * API version 4.0:
  *  - Change string handling to never transfer ownership of allocations.
@@ -305,7 +306,7 @@ int openconnect_set_http_proxy(struct openconnect_info *vpninfo,
 			       const char *proxy);
 int openconnect_passphrase_from_fsid(struct openconnect_info *vpninfo);
 int openconnect_obtain_cookie(struct openconnect_info *vpninfo);
-void openconnect_init_ssl(void);
+int openconnect_init_ssl(void);
 
 /* These are strictly cosmetic. The strings differ depending on
  * whether OpenSSL or GnuTLS is being used. And even depending on the
diff --git a/openssl.c b/openssl.c
index 6bbd267b..a08f591f 100644
--- a/openssl.c
+++ b/openssl.c
@@ -1547,15 +1547,18 @@ void openconnect_close_https(struct openconnect_info *vpninfo, int final)
 	}
 }
 
-void openconnect_init_ssl(void)
+int openconnect_init_ssl(void)
 {
 #ifdef _WIN32
-	openconnect__win32_sock_init();
+	int ret = openconnect__win32_sock_init();
+	if (ret)
+		return ret;
 #endif
 	SSL_library_init();
 	ERR_clear_error();
 	SSL_load_error_strings();
 	OpenSSL_add_all_algorithms();
+	return 0;
 }
 
 char *openconnect_get_cert_details(struct openconnect_info *vpninfo,