diff --git a/src/3rdparty/squirrel/include/squirrel.h b/src/3rdparty/squirrel/include/squirrel.h
index bbda8f72da..cb768cf5cb 100644
--- a/src/3rdparty/squirrel/include/squirrel.h
+++ b/src/3rdparty/squirrel/include/squirrel.h
@@ -164,9 +164,9 @@ typedef struct tagSQObject
 }SQObject;
 
 typedef struct tagSQStackInfos{
-	const SQChar* funcname;
-	const SQChar* source;
-	SQInteger line;
+	std::string_view funcname;
+	std::string_view source;
+	SQInteger line = -1;
 }SQStackInfos;
 
 typedef struct SQVM* HSQUIRRELVM;
@@ -190,8 +190,8 @@ typedef struct tagSQRegFunction{
 
 typedef struct tagSQFunctionInfo {
 	SQUserPointer funcid;
-	const SQChar *name;
-	const SQChar *source;
+	std::string_view name;
+	std::string_view source;
 }SQFunctionInfo;
 
 
diff --git a/src/3rdparty/squirrel/sqstdlib/sqstdaux.cpp b/src/3rdparty/squirrel/sqstdlib/sqstdaux.cpp
index a8abf8be79..f5763589c2 100644
--- a/src/3rdparty/squirrel/sqstdlib/sqstdaux.cpp
+++ b/src/3rdparty/squirrel/sqstdlib/sqstdaux.cpp
@@ -21,21 +21,17 @@ void sqstd_printcallstack(HSQUIRRELVM v)
 		pf(v,"\nCALLSTACK\n");
 		while(SQ_SUCCEEDED(sq_stackinfos(v,level,&si)))
 		{
-			const SQChar *fn="unknown";
-			const SQChar *src="unknown";
-			if(si.funcname)fn=si.funcname;
-			if(si.source) {
+			std::string_view fn="unknown";
+			std::string_view src="unknown";
+			if(!si.funcname.empty())fn=si.funcname;
+			if(!si.source.empty()) {
 				/* We don't want to bother users with absolute paths to all AI files.
 				 * Since the path only reaches NoAI code in a formatted string we have
 				 * to strip it here. Let's hope nobody installs openttd in a subdirectory
 				 * of a directory named /ai/. */
-				src = strstr(si.source, "\\ai\\");
-				if (!src) src = strstr(si.source, "/ai/");
-				if (src) {
-					src += 4;
-				} else {
-					src = si.source;
-				}
+				auto p = si.source.find("\\ai\\");
+				if (p == std::string_view::npos) p = si.source.find("/ai/");
+				src = (p == std::string_view::npos) ? si.source : si.source.substr(p + 4);
 			}
 			pf(v,fmt::format("*FUNCTION [{}()] {} line [{}]\n",fn,src,si.line));
 			level++;
diff --git a/src/3rdparty/squirrel/squirrel/sqdebug.cpp b/src/3rdparty/squirrel/squirrel/sqdebug.cpp
index d06696c485..cc5c21316c 100644
--- a/src/3rdparty/squirrel/squirrel/sqdebug.cpp
+++ b/src/3rdparty/squirrel/squirrel/sqdebug.cpp
@@ -37,7 +37,7 @@ SQRESULT sq_stackinfos(HSQUIRRELVM v, SQInteger level, SQStackInfos *si)
 {
 	SQInteger cssize = v->_callsstacksize;
 	if (cssize > level) {
-		memset(si, 0, sizeof(SQStackInfos));
+		*si = {};
 		SQVM::CallInfo &ci = v->_callsstack[cssize-level-1];
 		switch (type(ci._closure)) {
 		case OT_CLOSURE:{
diff --git a/src/script/squirrel_std.cpp b/src/script/squirrel_std.cpp
index a926dcde14..d00c2ca023 100644
--- a/src/script/squirrel_std.cpp
+++ b/src/script/squirrel_std.cpp
@@ -48,13 +48,9 @@ SQInteger SquirrelStd::require(HSQUIRRELVM vm)
 	/* Get the script-name of the current file, so we can work relative from it */
 	SQStackInfos si;
 	sq_stackinfos(vm, 1, &si);
-	if (si.source == nullptr) {
-		Debug(misc, 0, "[squirrel] Couldn't detect the script-name of the 'require'-caller; this should never happen!");
-		return SQ_ERROR;
-	}
 
 	/* Keep the dir, remove the rest */
-	std::string path = si.source;
+	std::string path{si.source};
 	auto p = path.find_last_of(PATHSEPCHAR);
 	/* Keep the PATHSEPCHAR there, remove the rest */
 	if (p != std::string::npos) path.erase(p + 1);