diff --git a/decoder_test.go b/decoder_test.go
index 89712fd..36e85f6 100644
--- a/decoder_test.go
+++ b/decoder_test.go
@@ -25,8 +25,9 @@ func TestDecode_interface(t *testing.T) {
 			"basic_squish.hcl",
 			false,
 			map[string]interface{}{
-				"foo": "bar",
-				"bar": "${file(\"bing/bong.txt\")}",
+				"foo":     "bar",
+				"bar":     "${file(\"bing/bong.txt\")}",
+				"foo-bar": "baz",
 			},
 		},
 		{
diff --git a/hcl/lex.go b/hcl/lex.go
index 674f509..8d710e6 100644
--- a/hcl/lex.go
+++ b/hcl/lex.go
@@ -170,7 +170,7 @@ func (x *hclLex) lexId(yylval *hclSymType) int {
 			break
 		}
 
-		if !unicode.IsDigit(c) && !unicode.IsLetter(c) && c != '_' {
+		if !unicode.IsDigit(c) && !unicode.IsLetter(c) && c != '_' && c != '-' {
 			x.backup()
 			break
 		}
diff --git a/test-fixtures/basic_squish.hcl b/test-fixtures/basic_squish.hcl
index 9b1c9e4..363697b 100644
--- a/test-fixtures/basic_squish.hcl
+++ b/test-fixtures/basic_squish.hcl
@@ -1,2 +1,3 @@
 foo="bar"
 bar="${file("bing/bong.txt")}"
+foo-bar="baz"