diff --git a/spec/issues/github_issue_44_spec.cr b/spec/issues/github_issue_44_spec.cr
index d1b9716..da6cbf3 100644
--- a/spec/issues/github_issue_44_spec.cr
+++ b/spec/issues/github_issue_44_spec.cr
@@ -26,12 +26,15 @@ Spectator.describe "GitHub Issue #44" do
   # Original issue uses keyword arguments in place of positional arguments.
   context "keyword arguments in place of positional arguments" do
     before_each do
-      expect(Process).to receive(:run).with(command, shell: true, output: :pipe).and_raise(exception)
+      pipe = Process::Redirect::Pipe
+      expect(Process).to receive(:run).with(command, shell: true, output: pipe).and_raise(exception)
     end
 
-    it "must stub Process.run", skip: "Keyword arguments in place of positional arguments not supported with expect-receive" do
-      Process.run(command, shell: true, output: :pipe) do |_process|
-      end
+    it "must stub Process.run" do
+      expect do
+        Process.run(command, shell: true, output: :pipe) do |_process|
+        end
+      end.to raise_error(File::NotFoundError, "File not found")
     end
   end
 end
diff --git a/src/spectator/mocks/arguments.cr b/src/spectator/mocks/arguments.cr
index f9c6e19..fcb74f4 100644
--- a/src/spectator/mocks/arguments.cr
+++ b/src/spectator/mocks/arguments.cr
@@ -90,9 +90,10 @@ module Spectator
 
       i = 0
       other.args.each do |k, v2|
+        break if i >= positional.size
         next if kwargs.has_key?(k) # Covered by named arguments.
 
-        v1 = positional.fetch(i) { return false }
+        v1 = positional[i]
         i += 1
         return false unless v1 === v2
       end