diff --git a/apps/openmw_tests/mwscript/testscripts.cpp b/apps/openmw_tests/mwscript/testscripts.cpp
index b9e422daed..1cc85e40ae 100644
--- a/apps/openmw_tests/mwscript/testscripts.cpp
+++ b/apps/openmw_tests/mwscript/testscripts.cpp
@@ -1,4 +1,6 @@
 #include <gtest/gtest.h>
+
+#include <array>
 #include <sstream>
 
 #include "testutils.hpp"
@@ -126,6 +128,31 @@ player -> addSpell "fire_bite", 645
 
 PositionCell "Rabenfels, Taverne" 4480.000 3968.000 15820.000 0
 
+End)mwscript";
+
+    const std::string sScript5 = R"mwscript(Begin messagebox_format_script
+
+float fVal
+
+set fVal to 12.34
+
+MessageBox "hello world"
+MessageBox "%.0f" fVal
+MessageBox "a %03.0f b" fVal
+MessageBox "%+04.0f" fVal
+MessageBox "%+4.0f" fVal
+MessageBox "%+ 4.0f" fVal
+MessageBox "%0+ 4.0f" fVal
+MessageBox "%0+ #4.0f" fVal
+MessageBox "%- 5.0f" fVal
+
+MessageBox "%g" fVal
+MessageBox "%.3g" fVal
+MessageBox "%.5g" fVal
+MessageBox "%#.5g" fVal
+MessageBox "%-5g" fVal
+MessageBox "%- 5g" fVal
+
 End)mwscript";
 
     const std::string sIssue587 = R"mwscript(Begin stalresetScript
@@ -579,6 +606,43 @@ End)mwscript";
         EXPECT_FALSE(!compile(sScript4));
     }
 
+    TEST_F(MWScriptTest, mwscript_test_messagebox_format)
+    {
+        if (const auto script = compile(sScript5))
+        {
+            TestInterpreterContext context;
+            run(*script, context);
+            using std::string_view_literals::operator""sv;
+            constexpr std::array expected{
+                "hello world"sv,
+                "12"sv,
+                "a 012 b"sv,
+                "+012"sv,
+                " +12"sv,
+                " +12"sv,
+                "+012"sv,
+                "+12."sv,
+                " 12  "sv,
+
+                "12.34"sv,
+                "12.3"sv,
+                "12.34"sv,
+                "12.340"sv,
+                "12.34"sv,
+                " 12.34"sv,
+            };
+            for (std::size_t i = 0; i < context.getMessages().size(); i++)
+            {
+                std::string_view message = context.getMessages()[i];
+                EXPECT_EQ(expected.at(i), message);
+            }
+        }
+        else
+        {
+            FAIL();
+        }
+    }
+
     TEST_F(MWScriptTest, mwscript_test_587)
     {
         EXPECT_FALSE(!compile(sIssue587));
diff --git a/apps/openmw_tests/mwscript/testutils.hpp b/apps/openmw_tests/mwscript/testutils.hpp
index ba22156f56..8ad571b6ee 100644
--- a/apps/openmw_tests/mwscript/testutils.hpp
+++ b/apps/openmw_tests/mwscript/testutils.hpp
@@ -145,8 +145,11 @@ namespace
     {
         LocalVariables mLocals;
         std::map<ESM::RefId, GlobalVariables> mMembers;
+        std::vector<std::string> mMessages;
 
     public:
+        const std::vector<std::string>& getMessages() { return mMessages; }
+
         ESM::RefId getTarget() const override { return ESM::RefId(); }
 
         int getLocalShort(int index) const override { return mLocals.getShort(index); }
@@ -161,7 +164,10 @@ namespace
 
         void setLocalFloat(int index, float value) override { mLocals.setFloat(index, value); }
 
-        void messageBox(std::string_view message, const std::vector<std::string>& buttons) override {}
+        void messageBox(std::string_view message, const std::vector<std::string>& buttons) override
+        {
+            mMessages.emplace_back(message);
+        }
 
         void report(const std::string& message) override {}