diff --git a/src/C4Group.cpp b/src/C4Group.cpp
index 3655193f..0646b19d 100644
--- a/src/C4Group.cpp
+++ b/src/C4Group.cpp
@@ -1610,7 +1610,7 @@ bool C4Group::DeleteEntry(const char *szFilename, bool fRecycle)
 	case GRPF_Folder:
 		StdFile.Close();
 		char szPath[_MAX_FNAME + 1];
-		FormatWithNull(szPath, "{}" DirSep "{}", FileName, szFilename);
+		FormatWithNull(szPath, "{}" DirSep "{}", +FileName, szFilename);
 
 		if (fRecycle)
 		{
@@ -1781,7 +1781,7 @@ bool C4Group::ExtractEntry(const char *szFilename, const char *szExtractTo)
 		break;
 	case GRPF_Folder: // Copy item from folder to target
 		char szPath[_MAX_FNAME + 1];
-		FormatWithNull(szPath, "{}" DirSep "{}", FileName, szFilename);
+		FormatWithNull(szPath, "{}" DirSep "{}", +FileName, szFilename);
 		if (!CopyItem(szPath, szTargetFName))
 			return Error("ExtractEntry: Cannot copy item");
 		break;
@@ -2194,7 +2194,7 @@ uint32_t C4Group::EntryTime(const char *szFilename)
 		break;
 	case GRPF_Folder:
 		char szPath[_MAX_FNAME + 1];
-		FormatWithNull(szPath, "{}" DirSep "{}", FileName, szFilename);
+		FormatWithNull(szPath, "{}" DirSep "{}", +FileName, szFilename);
 		iTime = FileTime(szPath);
 		break;
 	}
@@ -2390,7 +2390,7 @@ bool C4Group::EnsureChildFilePtr(C4Group *pChild)
 
 	// Open standard file is not the child file ...or StdFile ptr does not match pChild->FilePtr
 	char szChildPath[_MAX_PATH + 1];
-	FormatWithNull(szChildPath, "{}" DirSep "{}", FileName, GetFilename(pChild->FileName));
+	FormatWithNull(szChildPath, "{}" DirSep "{}", +FileName, GetFilename(pChild->FileName));
 	if (!ItemIdentical(StdFile.Name, szChildPath))
 	{
 		// Reopen correct child stdfile
diff --git a/src/C4Language.cpp b/src/C4Language.cpp
index ce66b919..be6bf39c 100644
--- a/src/C4Language.cpp
+++ b/src/C4Language.cpp
@@ -58,7 +58,7 @@ bool C4Language::Init()
 	if (PackDirectory.Open(C4CFN_Languages))
 		while (PackDirectory.FindNextEntry("*.c4g", strEntry))
 		{
-			FormatWithNull(strPackFilename, "{}" DirSep "{}", C4CFN_Languages, strEntry);
+			FormatWithNull(strPackFilename, "{}" DirSep "{}", +C4CFN_Languages, +strEntry);
 			pPack = new C4Group();
 			if (pPack->Open(strPackFilename))
 			{
diff --git a/src/C4Network2.cpp b/src/C4Network2.cpp
index 78095d4d..56734dd3 100644
--- a/src/C4Network2.cpp
+++ b/src/C4Network2.cpp
@@ -1951,7 +1951,7 @@ bool C4Network2::CreateDynamic(bool fInit)
 	Log(C4ResStrTableKey::IDS_NET_SAVING);
 	// compose file name
 	char szDynamicBase[_MAX_PATH + 1], szDynamicFilename[_MAX_PATH + 1];
-	FormatWithNull(szDynamicBase, "{}Dyn{}", Config.Network.WorkPath, GetFilename(Game.ScenarioFilename), _MAX_PATH);
+	FormatWithNull(szDynamicBase, "{}Dyn{}", +Config.Network.WorkPath, GetFilename(Game.ScenarioFilename), _MAX_PATH);
 	if (!ResList.FindTempResFileName(szDynamicBase, szDynamicFilename))
 		Log(C4ResStrTableKey::IDS_NET_SAVE_ERR_CREATEDYNFILE);
 	// save dynamic data
diff --git a/src/C4ScriptHost.cpp b/src/C4ScriptHost.cpp
index f4b66529..e5956620 100644
--- a/src/C4ScriptHost.cpp
+++ b/src/C4ScriptHost.cpp
@@ -194,10 +194,10 @@ void C4DefScriptHost::AfterLink()
 		for (int32_t cnt = 0; cnt < Def->ActNum; cnt++)
 		{
 			C4ActionDef *pad = &Def->ActMap[cnt];
-			FormatWithNull(WhereStr, "Action {}: StartCall", pad->Name); pad->StartCall = GetSFuncWarn(pad->SStartCall, CallAccess, WhereStr);
-			FormatWithNull(WhereStr, "Action {}: PhaseCall", pad->Name); pad->PhaseCall = GetSFuncWarn(pad->SPhaseCall, CallAccess, WhereStr);
-			FormatWithNull(WhereStr, "Action {}: EndCall",   pad->Name); pad->EndCall   = GetSFuncWarn(pad->SEndCall,   CallAccess, WhereStr);
-			FormatWithNull(WhereStr, "Action {}: AbortCall", pad->Name); pad->AbortCall = GetSFuncWarn(pad->SAbortCall, CallAccess, WhereStr);
+			FormatWithNull(WhereStr, "Action {}: StartCall", +pad->Name); pad->StartCall = GetSFuncWarn(pad->SStartCall, CallAccess, WhereStr);
+			FormatWithNull(WhereStr, "Action {}: PhaseCall", +pad->Name); pad->PhaseCall = GetSFuncWarn(pad->SPhaseCall, CallAccess, WhereStr);
+			FormatWithNull(WhereStr, "Action {}: EndCall",   +pad->Name); pad->EndCall   = GetSFuncWarn(pad->SEndCall,   CallAccess, WhereStr);
+			FormatWithNull(WhereStr, "Action {}: AbortCall", +pad->Name); pad->AbortCall = GetSFuncWarn(pad->SAbortCall, CallAccess, WhereStr);
 		}
 		Def->TimerCall = GetSFuncWarn(Def->STimerCall, CallAccess, "TimerCall");
 	}
diff --git a/src/C4Strings.h b/src/C4Strings.h
index fb3e1a33..3f16bf81 100644
--- a/src/C4Strings.h
+++ b/src/C4Strings.h
@@ -181,19 +181,19 @@ struct C4NullableBasicStringView
 
 using C4NullableStringView = C4NullableBasicStringView<char>;
 
-template<std::size_t N, typename...Args>
+template<std::size_t N, typename...Args> requires (!std::disjunction_v<std::is_array<std::remove_cvref_t<Args>>...>)
 void FormatWithNull(char(&buf)[N], const std::format_string<Args...> fmt, Args&&...args)
 {
 	*std::format_to_n(buf, N - 1, fmt, std::forward<Args>(args)...).out = '\0';
 }
 
-template<std::size_t N, typename...Args>
+template<std::size_t N, typename...Args> requires (!std::disjunction_v<std::is_array<std::remove_cvref_t<Args>>...>)
 void FormatWithNull(std::array<char, N> &buf, const std::format_string<Args...> fmt, Args&&...args)
 {
 	*std::format_to_n(buf.begin(), N - 1, fmt, std::forward<Args>(args)...).out = '\0';
 }
 
-template<std::size_t N, typename... Args>
+template<std::size_t N, typename... Args> requires (!std::disjunction_v<std::is_array<std::remove_cvref_t<Args>>...>)
 void FormatWithNull(const std::span<char, N> buf, const std::format_string<Args...> fmt, Args &&...args)
 {
 	*std::format_to_n(buf.begin(), buf.size() - 1, fmt, std::forward<Args>(args)...).out = '\0';