diff --git a/packer/README.rst b/packer/README.rst
index 61c6678..9a73701 100644
--- a/packer/README.rst
+++ b/packer/README.rst
@@ -21,6 +21,12 @@ If you want logs:
     PACKER_LOG=1 packer build template.json
 
 
+Packer versions 1.6.0 or later do not accept templates
+that use the ``iso_checksum_type`` attribute.
+To use these newer versions, you must delete the line
+containing ``iso_checksum_type`` from the template.json.
+
+
 Conventions
 ************
 User should be gns3 or root.
diff --git a/packer/alpine-linux/README.rst b/packer/alpine-linux/README.rst
index 2964c6f..18dc096 100644
--- a/packer/alpine-linux/README.rst
+++ b/packer/alpine-linux/README.rst
@@ -5,6 +5,16 @@ For building an Alpine appliance.
 
 https://alpinelinux.org/
 
+
+Packer Version Dependency
+*************************
+
+Packer versions 1.6.0 or later do not accept templates
+that use the ``iso_checksum_type`` attribute.
+To use these newer versions, you must delete the line
+containing ``iso_checksum_type`` from alpine.json.
+
+
 Alpine CLI installation
 ***********************
 
diff --git a/packer/tinycore-linux/README.rst b/packer/tinycore-linux/README.rst
index 67f8869..51527f3 100644
--- a/packer/tinycore-linux/README.rst
+++ b/packer/tinycore-linux/README.rst
@@ -5,6 +5,17 @@ For building a MicroCore / TinyCore appliance.
 
 http://tinycorelinux.net/
 
+
+Packer Version Dependency
+*************************
+
+Packer versions 1.6.0 or later do not accept templates
+that use the ``iso_checksum_type`` attribute.
+To use these newer versions, you must delete the line
+containing ``iso_checksum_type`` from core-linux.json,
+core64-linux.json and tinycore-linux.json.
+
+
 Clean core Linux installation
 *****************************