2 files changed, 4 insertions, 0 deletions
diff --git a/tinyrtc.c b/tinyrtc.c
index 98aba07..1b6856a 100644
--- a/tinyrtc.c
+++ b/tinyrtc.c
@@ -13,6 +13,8 @@
  *    and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
+ * 4. This software may not be used for commercial purposes. For a commercial
+ *    license, contact the copyright holder.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
diff --git a/tinyrtc.h b/tinyrtc.h
index 02c8459..8a961e3 100644
--- a/tinyrtc.h
+++ b/tinyrtc.h
@@ -13,6 +13,8 @@
  *    and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
+ * 4. This software may not be used for commercial purposes. For a commercial
+ *    license, contact the copyright holder.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF