diff --git a/modules/comment.module b/modules/comment.module
index 740bc1131ab..4b1b0a64033 100644
--- a/modules/comment.module
+++ b/modules/comment.module
@@ -458,7 +458,7 @@ function comment_validate_form($edit) {
   /*
   ** Validate filter format
   */
-  if (!filter_access($edit['format'])) {
+  if (array_key_exists('format', $edit) && !filter_access($edit['format'])) {
     form_set_error('format', t('The supplied input format is invalid.'));
   }
 
diff --git a/modules/comment/comment.module b/modules/comment/comment.module
index 740bc1131ab..4b1b0a64033 100644
--- a/modules/comment/comment.module
+++ b/modules/comment/comment.module
@@ -458,7 +458,7 @@ function comment_validate_form($edit) {
   /*
   ** Validate filter format
   */
-  if (!filter_access($edit['format'])) {
+  if (array_key_exists('format', $edit) && !filter_access($edit['format'])) {
     form_set_error('format', t('The supplied input format is invalid.'));
   }
 
diff --git a/modules/node.module b/modules/node.module
index f6e7c586973..a0e67e7105a 100644
--- a/modules/node.module
+++ b/modules/node.module
@@ -1097,7 +1097,7 @@ function node_validate($node) {
   node_invoke_nodeapi($node, 'validate');
 
   // Check input format access
-  if (!filter_access($node->format)) {
+  if (array_key_exists('format', $node) && !filter_access($node->format)) {
     form_set_error('format', t('The supplied input format is invalid.'));
   }
 
diff --git a/modules/node/node.module b/modules/node/node.module
index f6e7c586973..a0e67e7105a 100644
--- a/modules/node/node.module
+++ b/modules/node/node.module
@@ -1097,7 +1097,7 @@ function node_validate($node) {
   node_invoke_nodeapi($node, 'validate');
 
   // Check input format access
-  if (!filter_access($node->format)) {
+  if (array_key_exists('format', $node) && !filter_access($node->format)) {
     form_set_error('format', t('The supplied input format is invalid.'));
   }