diff --git a/lib/pegjs/html/glimmer-tag-string.pegjs b/lib/pegjs/html/glimmer-tag-string.pegjs
new file mode 100644
index 0000000..89483e9
--- /dev/null
+++ b/lib/pegjs/html/glimmer-tag-string.pegjs
@@ -0,0 +1,8 @@
+@import "../non-separator-colon.pegjs" as nonSeparatorColon
+
+start = tagString
+
+tagString 'valid tag string'
+  = c:$tagChar+
+
+tagChar = [_a-zA-Z0-9-.] / nonSeparatorColon / '@'
diff --git a/lib/pegjs/html/tag-component.pegjs b/lib/pegjs/html/tag-component.pegjs
index 8c7be34..7e4b36c 100644
--- a/lib/pegjs/html/tag-component.pegjs
+++ b/lib/pegjs/html/tag-component.pegjs
@@ -3,7 +3,7 @@
 @import "./attribute.pegjs" as attribute
 @import "./attribute-bracketed.pegjs" as bracketedAttribute
 @import "./attribute-shorthand.pegjs" as shorthandAttributes
-@import "./tag-string.pegjs" as tagString
+@import "./glimmer-tag-string.pegjs" as glimmerTagString
 @import "../mustache/ast/in-tag.pegjs" as inTagMustache
 @import "../syntax/block-params.pegjs" as blockParamsRaw
 @import "../whitespace.pegjs" as _
@@ -29,7 +29,7 @@ htmlStart
 
 // @TODO / coercion
 componentTag
-  = '%' _ s:tagString
+  = '%' _ s:glimmerTagString
 {
   return s;
 }
diff --git a/tests/integration/glimmer/blocks-test.js b/tests/integration/glimmer/blocks-test.js
index 8da915e..2e32fde 100644
--- a/tests/integration/glimmer/blocks-test.js
+++ b/tests/integration/glimmer/blocks-test.js
@@ -20,7 +20,7 @@ module('glimmer: blocks', function (hooks) {
 
     assert.compilesTo(emblem,
       '<MyComponent @value={{foo}} as |comp1 @comp2|>{{comp.name}}</MyComponent>');
-  });
+  });  
 
   test('recursive nesting part 2', function (assert) {
     const emblem = w(
@@ -33,4 +33,15 @@ module('glimmer: blocks', function (hooks) {
     assert.compilesTo(emblem, '<my-comp-1><my-comp-2><p>Hello</p></my-comp-2></my-comp-1>');
   });
 
+
+  test("block params with nested comp", function (assert) {
+    const emblem = w(
+      "%MyComponent @value=foo as |comp1 @comp2|",
+      "  %comp.name @value1=foo"
+    );
+
+    assert.compilesTo(emblem,
+      '<MyComponent @value={{foo}} as |comp1 @comp2|><comp.name @value1={{foo}}></comp.name></MyComponent>');
+  }); 
+
 });