diff --git a/spec/ameba/rule/lint/spec_filename_spec.cr b/spec/ameba/rule/lint/spec_filename_spec.cr
index 44d51dc8e..30a2c57de 100644
--- a/spec/ameba/rule/lint/spec_filename_spec.cr
+++ b/spec/ameba/rule/lint/spec_filename_spec.cr
@@ -4,6 +4,16 @@ module Ameba::Rule::Lint
   subject = SpecFilename.new
 
   describe SpecFilename do
+    it "passes if relative file path does not start with `spec/`" do
+      expect_no_issues subject, code: "", path: "src/spec/foo.cr"
+      expect_no_issues subject, code: "", path: "src/spec/foo/bar.cr"
+    end
+
+    it "passes if file extension is not `.cr`" do
+      expect_no_issues subject, code: "", path: "spec/foo.json"
+      expect_no_issues subject, code: "", path: "spec/foo/bar.json"
+    end
+
     it "passes if filename is correct" do
       expect_no_issues subject, code: "", path: "spec/foo_spec.cr"
       expect_no_issues subject, code: "", path: "spec/foo/bar_spec.cr"
diff --git a/src/ameba/rule/lint/spec_filename.cr b/src/ameba/rule/lint/spec_filename.cr
index 9711806f7..32492a6fa 100644
--- a/src/ameba/rule/lint/spec_filename.cr
+++ b/src/ameba/rule/lint/spec_filename.cr
@@ -8,6 +8,8 @@ module Ameba::Rule::Lint
   # ```
   # Lint/SpecFilename:
   #   Enabled: true
+  #   IgnoredDirs: [spec/support spec/fixtures spec/data]
+  #   IgnoredFilenames: [spec_helper]
   # ```
   class SpecFilename < Base
     properties do
@@ -26,8 +28,10 @@ module Ameba::Rule::Lint
       name = path_.stem
       path = path_.to_s
 
-      # check files only within spec/ directory
+      # check only files within spec/ directory
       return unless path.starts_with?("spec/")
+      # check only files with `.cr` extension
+      return unless path.ends_with?(".cr")
       # ignore files having `_spec` suffix
       return if name.ends_with?("_spec")