diff --git a/build/VStudio/testing/fsbench.vcxproj b/build/VStudio/testing/fsbench.vcxproj
index 699f16fd..03f96ba3 100644
--- a/build/VStudio/testing/fsbench.vcxproj
+++ b/build/VStudio/testing/fsbench.vcxproj
@@ -146,6 +146,7 @@
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
@@ -161,6 +162,7 @@
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
@@ -176,6 +178,7 @@
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
@@ -195,6 +198,7 @@
       <SubSystem>Console</SubSystem>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
@@ -214,6 +218,7 @@
       <SubSystem>Console</SubSystem>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
@@ -233,6 +238,7 @@
       <SubSystem>Console</SubSystem>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>ntdll.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
diff --git a/ext/tlib/testsuite.c b/ext/tlib/testsuite.c
index ed0c946d..ad5d1c73 100644
--- a/ext/tlib/testsuite.c
+++ b/ext/tlib/testsuite.c
@@ -201,16 +201,23 @@ void tlib_run_tests(int argc, char *argv[])
 }
 void tlib__assert(const char *func, const char *file, int line, const char *expr)
 {
+    char extra_buf[256] = "";
 #if defined(_WIN64) || defined(_WIN32)
+    long __stdcall RtlGetLastNtStatus(void);
+    unsigned long __stdcall RtlGetLastWin32Error(void);
+    snprintf(extra_buf, sizeof extra_buf,
+        " (err=%lx:%lu)",
+        RtlGetLastNtStatus(),
+        RtlGetLastWin32Error());
     const char *p = strrchr(file, '\\');
 #else
     const char *p = strrchr(file, '/');
 #endif
     file = 0 != p ? p + 1 : file;
     if (0 == func)
-        test_printf("%sASSERT(%s) failed at: %s:%d\n", assert_buf, expr, file, line);
+        test_printf("%sASSERT(%s) failed at: %s:%d%s\n", assert_buf, expr, file, line, extra_buf);
     else
-        test_printf("%sASSERT(%s) failed at %s:%d:%s\n", assert_buf, expr, file, line, func);
+        test_printf("%sASSERT(%s) failed at %s:%d:%s%s\n", assert_buf, expr, file, line, func, extra_buf);
     if (0 != test_jmp)
         longjmp(*test_jmp, 1);
 }