diff --git a/lib/jekyll-compose/file_creator.rb b/lib/jekyll-compose/file_creator.rb
index 17a7e0e..2a33789 100644
--- a/lib/jekyll-compose/file_creator.rb
+++ b/lib/jekyll-compose/file_creator.rb
@@ -25,7 +25,7 @@ def file_path
       private
 
       def validate_should_write!
-        return Jekyll.logger.warn "A #{file.resource_type} already exists at #{file_path}".yellow if File.exist?(file_path) && !force
+        raise ArgumentError, "A #{file.resource_type} already exists at #{file_path}" if File.exist?(file_path) && !force
       end
 
       def ensure_directory_exists
diff --git a/spec/draft_spec.rb b/spec/draft_spec.rb
index f5759ba..908c785 100644
--- a/spec/draft_spec.rb
+++ b/spec/draft_spec.rb
@@ -63,9 +63,10 @@
       FileUtils.touch path
     end
 
-    it "displays a warning and abort" do
-      output = capture_stdout { described_class.process(args) }
-      expect(output).to include("A draft already exists at _drafts/an-existing-draft.md".yellow)
+    it "raises an error" do
+      expect(lambda {
+        capture_stdout { described_class.process(args) }
+      }).to raise_error("A draft already exists at _drafts/an-existing-draft.md")
     end
 
     it "overwrites if --force is given" do
diff --git a/spec/page_spec.rb b/spec/page_spec.rb
index a631886..fabb4bd 100644
--- a/spec/page_spec.rb
+++ b/spec/page_spec.rb
@@ -52,9 +52,10 @@
       FileUtils.touch path
     end
 
-    it "displays a warning" do
-      output = capture_stdout { described_class.process(args) }
-      expect(output).to include("A page already exists at #{filename}".yellow)
+    it "raises an error" do
+      expect(lambda {
+        capture_stdout { described_class.process(args) }
+      }).to raise_error("A page already exists at #{filename}")
     end
 
     it "overwrites if --force is given" do
diff --git a/spec/post_spec.rb b/spec/post_spec.rb
index f947af0..7f5d4fa 100644
--- a/spec/post_spec.rb
+++ b/spec/post_spec.rb
@@ -74,9 +74,10 @@
       FileUtils.touch path
     end
 
-    it "displays a warning" do
-      output = capture_stdout { described_class.process(args) }
-      expect(output).to include("A post already exists at _posts/#{filename}".yellow)
+    it "raises an error" do
+      expect(lambda {
+        capture_stdout { described_class.process(args) }
+      }).to raise_error("A post already exists at _posts/#{filename}")
     end
 
     it "overwrites if --force is given" do