diff --git a/website/pages/docs/builders/hyperv/iso.mdx b/website/pages/docs/builders/hyperv/iso.mdx
index a4b2aa09e..144cb3bac 100644
--- a/website/pages/docs/builders/hyperv/iso.mdx
+++ b/website/pages/docs/builders/hyperv/iso.mdx
@@ -33,8 +33,7 @@ to self-install. Still, the example serves to show the basic configuration:
 {
   "type": "hyperv-iso",
   "iso_url": "http://releases.ubuntu.com/12.04/ubuntu-12.04.5-server-amd64.iso",
-  "iso_checksum": "769474248a3897f4865817446f9a4a53",
-  "iso_checksum_type": "md5",
+  "iso_checksum": "md5:769474248a3897f4865817446f9a4a53",
   "ssh_username": "packer",
   "ssh_password": "packer",
   "shutdown_command": "echo 'packer' | sudo -S shutdown -P now"
@@ -205,8 +204,7 @@ Packer config:
       "boot_wait": "0s",
       "boot_command": ["a<wait>a<wait>a"],
       "iso_url": "http://download.microsoft.com/download/6/2/A/62A76ABB-9990-4EFC-A4FE-C7D698DAEB96/9600.16384.WINBLUE_RTM.130821-1623_X64FRE_SERVER_EVAL_EN-US-IRM_SSS_X64FREE_EN-US_DV5.ISO",
-      "iso_checksum_type": "md5",
-      "iso_checksum": "458ff91f8abc21b75cb544744bf92e6a",
+      "iso_checksum": "md5:458ff91f8abc21b75cb544744bf92e6a",
       "communicator": "winrm",
       "winrm_username": "vagrant",
       "winrm_password": "vagrant",
@@ -727,8 +725,7 @@ virtual switch with an `External` connection type.
     "memory": "1024",
     "disk_size": "21440",
     "iso_url": "http://releases.ubuntu.com/16.04/ubuntu-16.04.6-server-amd64.iso",
-    "iso_checksum_type": "sha1",
-    "iso_checksum": "056b7c15efc15bbbf40bf1a9ff1a3531fcbf70a2"
+    "iso_checksum": "sha1:056b7c15efc15bbbf40bf1a9ff1a3531fcbf70a2"
   },
   "builders": [
     {
@@ -737,7 +734,6 @@ virtual switch with an `External` connection type.
       "disk_size": "{{user `disk_size`}}",
       "guest_additions_mode": "disable",
       "iso_url": "{{user `iso_url`}}",
-      "iso_checksum_type": "{{user `iso_checksum_type`}}",
       "iso_checksum": "{{user `iso_checksum`}}",
       "communicator": "ssh",
       "ssh_username": "packer",
diff --git a/website/pages/docs/builders/hyperv/vmcx.mdx b/website/pages/docs/builders/hyperv/vmcx.mdx
index 7cf3b36b0..390bb6d92 100644
--- a/website/pages/docs/builders/hyperv/vmcx.mdx
+++ b/website/pages/docs/builders/hyperv/vmcx.mdx
@@ -230,8 +230,7 @@ Packer config:
       "boot_wait": "0s",
       "boot_command": ["a<wait>a<wait>a"],
       "iso_url": "http://download.microsoft.com/download/6/2/A/62A76ABB-9990-4EFC-A4FE-C7D698DAEB96/9600.16384.WINBLUE_RTM.130821-1623_X64FRE_SERVER_EVAL_EN-US-IRM_SSS_X64FREE_EN-US_DV5.ISO",
-      "iso_checksum_type": "md5",
-      "iso_checksum": "458ff91f8abc21b75cb544744bf92e6a",
+      "iso_checksum": "md5:458ff91f8abc21b75cb544744bf92e6a",
       "communicator": "winrm",
       "winrm_username": "vagrant",
       "winrm_password": "vagrant",
@@ -752,8 +751,7 @@ virtual switch with an `External` connection type.
     "memory": "1024",
     "disk_size": "21440",
     "iso_url": "http://releases.ubuntu.com/16.04/ubuntu-16.04.1-server-amd64.iso",
-    "iso_checksum_type": "sha1",
-    "iso_checksum": "DE5EE8665048F009577763EFBF4A6F0558833E59"
+    "iso_checksum": "sha1:DE5EE8665048F009577763EFBF4A6F0558833E59"
   },
   "builders": [
     {
@@ -762,7 +760,6 @@ virtual switch with an `External` connection type.
       "disk_size": "{{user `disk_size`}}",
       "guest_additions_mode": "disable",
       "iso_url": "{{user `iso_url`}}",
-      "iso_checksum_type": "{{user `iso_checksum_type`}}",
       "iso_checksum": "{{user `iso_checksum`}}",
       "communicator": "ssh",
       "ssh_username": "packer",
diff --git a/website/pages/docs/builders/proxmox.mdx b/website/pages/docs/builders/proxmox.mdx
index 339a7accd..58df331a3 100644
--- a/website/pages/docs/builders/proxmox.mdx
+++ b/website/pages/docs/builders/proxmox.mdx
@@ -59,12 +59,11 @@ builder.
 - `iso_storage_pool` (string) - Proxmox storage pool onto which to upload
   the ISO file.
 
-- `iso_checksum` (string) - Checksum of the ISO file.
-
-- `iso_checksum_type` (string) - Type of the checksum. Can be md5, sha1,
-  sha256, sha512 or none. Corruption of large files, such as ISOs, can occur
-  during transfer from time to time. As such, setting this to none is not
-  recommended.
+- `iso_checksum` (string) - Checksum of the ISO file. Type of the checksum
+  is infered based on string length, or can be explicitly prefixed with
+  md5:, sha1:, sha256:, sha512: or set to none. Corruption of large files,
+  such as ISOs, can occur during transfer from time to time. As such,
+  setting this to none is not recommended.
 
 ### Optional:
 
diff --git a/website/pages/docs/builders/virtualbox/iso.mdx b/website/pages/docs/builders/virtualbox/iso.mdx
index 05d14c717..b22dc0444 100644
--- a/website/pages/docs/builders/virtualbox/iso.mdx
+++ b/website/pages/docs/builders/virtualbox/iso.mdx
@@ -36,8 +36,7 @@ self-install. Still, the example serves to show the basic configuration:
   "type": "virtualbox-iso",
   "guest_os_type": "Ubuntu_64",
   "iso_url": "http://releases.ubuntu.com/12.04/ubuntu-12.04.5-server-amd64.iso",
-  "iso_checksum": "769474248a3897f4865817446f9a4a53",
-  "iso_checksum_type": "md5",
+  "iso_checksum": "md5:769474248a3897f4865817446f9a4a53",
   "ssh_username": "packer",
   "ssh_password": "packer",
   "shutdown_command": "echo 'packer' | sudo -S shutdown -P now"
@@ -52,8 +51,7 @@ self-install. Still, the example serves to show the basic configuration:
 source "virtualbox-iso" "basic-example" {
   guest_os_type = "Ubuntu_64"
   iso_url = "http://releases.ubuntu.com/12.04/ubuntu-12.04.5-server-amd64.iso"
-  iso_checksum = "769474248a3897f4865817446f9a4a53"
-  iso_checksum_type = "md5"
+  iso_checksum = "md5:769474248a3897f4865817446f9a4a53"
   ssh_username = "packer"
   ssh_password = "packer"
   shutdown_command = "echo 'packer' | sudo -S shutdown -P now"
diff --git a/website/pages/docs/post-processors/googlecompute-import.mdx b/website/pages/docs/post-processors/googlecompute-import.mdx
index 76987c897..71635b893 100644
--- a/website/pages/docs/post-processors/googlecompute-import.mdx
+++ b/website/pages/docs/post-processors/googlecompute-import.mdx
@@ -112,8 +112,7 @@ server was running in GCE with the nested hypervisor feature enabled.
       ],
       "disk_size": "15000",
       "format": "raw",
-      "iso_checksum_type": "sha256",
-      "iso_checksum": "ea1efdc692356b3346326f82e2f468903e8da59324fdee8b10eac4fea83f23fe",
+      "iso_checksum": "sha256:ea1efdc692356b3346326f82e2f468903e8da59324fdee8b10eac4fea83f23fe",
       "iso_url": "https://download-ib01.fedoraproject.org/pub/fedora/linux/releases/28/Server/x86_64/iso/Fedora-Server-netinst-x86_64-28-1.1.iso",
       "headless": "true",
       "http_directory": "http",