diff --git a/CHANGELOG.md b/CHANGELOG.md
index c1fa5fa6f..9b5f36e56 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,13 +3,14 @@
 
 1. [](#new)
     * Added `Session::regenerateId()` method to properly prevent session fixation issues
+    * Added configuration option `system.strict_mode.blueprint_compat` to maintain old `validation: strict` behavior [#1273](https://github.com/getgrav/grav/issues/1273)
 1. [](#improved)
     * Improved Flex events
 1. [](#bugfix)
-    * Fixed `validation: strict` not working in blueprints [#1273](https://github.com/getgrav/grav/issues/1273)
     * Fixed Flex Pages having broken `isFirst()`, `isLast()`, `prevSibling()`, `nextSibling()` and `adjacentSibling()`
-    * Fixed broken ordering sometimes when saving/moving visible `Flex Page`
+    * Fixed broken ordering sometimes when saving/moving visible `Flex Page` [#2837](https://github.com/getgrav/grav/issues/2837)
     * Fixed ordering being lost when saving modular `Flex Page`
+    * Fixed `validation: strict` not working in blueprints (see `system.strict_mode.blueprint_compat` setting) [#1273](https://github.com/getgrav/grav/issues/1273)
 
 # v1.7.0-rc.6
 ## 02/11/2020
diff --git a/system/blueprints/config/system.yaml b/system/blueprints/config/system.yaml
index c253a055b..70b8796a3 100644
--- a/system/blueprints/config/system.yaml
+++ b/system/blueprints/config/system.yaml
@@ -1438,6 +1438,18 @@ form:
             accounts.storage:
               type: hidden
 
+            strict_mode.blueprint_compat:
+              type: toggle
+              label: PLUGIN_ADMIN.STRICT_BLUEPRINT_COMPAT
+              highlight: 1
+              default: 1
+              help: PLUGIN_ADMIN.STRICT_BLUEPRINT_COMPAT_HELP
+              options:
+                1: PLUGIN_ADMIN.YES
+                0: PLUGIN_ADMIN.NO
+              validate:
+                type: bool
+
             strict_mode.yaml_compat:
               type: toggle
               label: PLUGIN_ADMIN.STRICT_YAML_COMPAT
diff --git a/system/config/system.yaml b/system/config/system.yaml
index 50e3b7a85..bf59e03cd 100644
--- a/system/config/system.yaml
+++ b/system/config/system.yaml
@@ -183,3 +183,4 @@ flex:
 strict_mode:
   yaml_compat: true                              # Grav 1.5+: Enables YAML backwards compatibility
   twig_compat: true                              # Grav 1.5+: Enables deprecated Twig autoescape setting (autoescape: false)
+  blueprint_compat: true                         # Grav 1.7+: Enables backward compatible strict support for blueprints
diff --git a/system/src/Grav/Common/Data/BlueprintSchema.php b/system/src/Grav/Common/Data/BlueprintSchema.php
index 45b6174c9..b37bbdb1a 100644
--- a/system/src/Grav/Common/Data/BlueprintSchema.php
+++ b/system/src/Grav/Common/Data/BlueprintSchema.php
@@ -9,6 +9,7 @@
 
 namespace Grav\Common\Data;
 
+use Grav\Common\Config\Config;
 use Grav\Common\Grav;
 use RocketTheme\Toolbox\ArrayTraits\Export;
 use RocketTheme\Toolbox\ArrayTraits\ExportInterface;
@@ -157,7 +158,13 @@ class BlueprintSchema extends BlueprintSchemaBase implements ExportInterface
                 $messages += $this->validateArray($child, $val, $strict);
             } elseif ($strict) {
                 // Undefined/extra item.
-                throw new \RuntimeException(sprintf('%s is not defined in blueprints', $key));
+                /** @var Config $config */
+                $config = Grav::instance()['config'];
+                if (!$config->get('system.strict_mode.blueprint_strict_compat', true)) {
+                    throw new \RuntimeException(sprintf('%s is not defined in blueprints', $key));
+                }
+
+                user_error(sprintf('Having extra key %s in your data is deprecated with blueprint having \'validation: strict\'', $key), E_USER_DEPRECATED);
             }
         }