diff --git a/dtls_time.c b/dtls_time.c
index 5d353b4f..982f5a1d 100644
--- a/dtls_time.c
+++ b/dtls_time.c
@@ -1,6 +1,6 @@
 /*******************************************************************************
  *
- * Copyright (c) 2011, 2012, 2013, 2014, 2015 Olaf Bergmann (TZI) and others.
+ * Copyright (c) 2011-2022 Olaf Bergmann (TZI) and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
@@ -20,67 +20,17 @@
  */
 
 #include "tinydtls.h"
-#include "dtls_time.h"
 
-#ifdef WITH_CONTIKI
-clock_time_t dtls_clock_offset;
+#if defined (WITH_CONTIKI)
+#include "platform-specific/dtls_time_contiki.c"
 
-void
-dtls_clock_init(void) {
-  clock_init();
-  dtls_clock_offset = clock_time();
-}
+#elif defined (RIOT_VERSION)
+#include "platform-specific/dtls_time_riot.c"
 
-void
-dtls_ticks(dtls_tick_t *t) {
-  *t = clock_time();
-}
+#elif defined (WITH_POSIX)
+#include "platform-specific/dtls_time_posix.c"
 
-#endif /* WITH_CONTIKI */
-
-#ifdef RIOT_VERSION
-dtls_tick_t dtls_clock_offset;
-
-void
-dtls_clock_init(void) {
-  dtls_clock_offset = xtimer_now64().ticks64;
-}
-
-void
-dtls_ticks(dtls_tick_t *t) {
-  *t = xtimer_now64().ticks64 -dtls_clock_offset;
-}
-
-#endif /* RIOT_VERSION */
-
-#ifdef WITH_POSIX
-time_t dtls_clock_offset;
-
-void
-dtls_clock_init(void) {
-#ifdef HAVE_TIME_H
-  dtls_clock_offset = time(NULL);
 #else
-#  ifdef __GNUC__
-  /* Issue a warning when using gcc. Other prepropressors do 
-   *  not seem to have a similar feature. */ 
-#   warning "cannot initialize clock"
-#  endif
-  dtls_clock_offset = 0;
-#endif
-}
+#error platform specific time functions not defined
 
-void dtls_ticks(dtls_tick_t *t) {
-#ifdef HAVE_SYS_TIME_H
-  struct timeval tv;
-  gettimeofday(&tv, NULL);
-  *t = (tv.tv_sec - dtls_clock_offset) * DTLS_TICKS_PER_SECOND 
-    + (tv.tv_usec * DTLS_TICKS_PER_SECOND / 1000000);
-#else
-#error "clock not implemented"
 #endif
-}
-
-#endif /* WITH_POSIX */
-
-
diff --git a/platform-specific/dtls_time_contiki.c b/platform-specific/dtls_time_contiki.c
new file mode 100644
index 00000000..d04ca7a1
--- /dev/null
+++ b/platform-specific/dtls_time_contiki.c
@@ -0,0 +1,31 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2011-2022 Olaf Bergmann (TZI) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
+ *
+ * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at 
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Olaf Bergmann  - initial API and implementation
+ *
+ *******************************************************************************/
+
+#include "tinydtls.h"
+#include "dtls_time.h"
+
+clock_time_t dtls_clock_offset;
+
+void
+dtls_clock_init(void) {
+  clock_init();
+  dtls_clock_offset = clock_time();
+}
+
+void
+dtls_ticks(dtls_tick_t *t) {
+  *t = clock_time();
+}
diff --git a/platform-specific/dtls_time_posix.c b/platform-specific/dtls_time_posix.c
new file mode 100644
index 00000000..eeb97f01
--- /dev/null
+++ b/platform-specific/dtls_time_posix.c
@@ -0,0 +1,47 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2011-2022 Olaf Bergmann (TZI) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
+ *
+ * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at 
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Olaf Bergmann  - initial API and implementation
+ *
+ *******************************************************************************/
+
+#include "tinydtls.h"
+#include "dtls_time.h"
+
+time_t dtls_clock_offset;
+
+void
+dtls_clock_init(void) {
+#ifdef HAVE_TIME_H
+  dtls_clock_offset = time(NULL);
+#else
+#  ifdef __GNUC__
+  /* Issue a warning when using gcc. Other prepropressors do 
+   *  not seem to have a similar feature. */ 
+#   warning "cannot initialize clock"
+#  endif
+  dtls_clock_offset = 0;
+#endif
+}
+
+void dtls_ticks(dtls_tick_t *t) {
+#ifdef HAVE_SYS_TIME_H
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  *t = (tv.tv_sec - dtls_clock_offset) * DTLS_TICKS_PER_SECOND 
+    + (tv.tv_usec * DTLS_TICKS_PER_SECOND / 1000000);
+#else
+#error "clock not implemented"
+#endif
+}
+
+
diff --git a/platform-specific/dtls_time_riot.c b/platform-specific/dtls_time_riot.c
new file mode 100644
index 00000000..798fd897
--- /dev/null
+++ b/platform-specific/dtls_time_riot.c
@@ -0,0 +1,30 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2011-2022 Olaf Bergmann (TZI) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
+ *
+ * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at 
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * Contributors:
+ *    Olaf Bergmann  - initial API and implementation
+ *
+ *******************************************************************************/
+
+#include "tinydtls.h"
+#include "dtls_time.h"
+
+dtls_tick_t dtls_clock_offset;
+
+void
+dtls_clock_init(void) {
+  dtls_clock_offset = xtimer_now64().ticks64;
+}
+
+void
+dtls_ticks(dtls_tick_t *t) {
+  *t = xtimer_now64().ticks64 -dtls_clock_offset;
+}