diff --git a/Changelog.md b/Changelog.md
index 459d26c3..1a2a2052 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -23,6 +23,11 @@ Note: Numbers starting with a "#" like #330 refer to the bugreport with that num
 * Updated Dear ImGui to 1.91.4
 * Fix scaling of Grabber cursor in Resurrection of Evil in non-4:3 resolutions (#637)
 * Add `com_disableAutoSaves` CVar: If set to `1`, Autosaves (when starting a level) are disabled (#620)
+* Add support for "nospecular" parm of lights, enabled by setting `"allow_nospecular" "1"` in a maps
+  worldspawn, or by setting the `r_allowNoSpecular` CVar to `1`.  
+  Note that this required changing the format of demos. dhewm3 can still play old demos, but ones
+  recorded with current dhewm3 are not compatible with older dhewm3 versions, original Doom3 or
+  other source ports (unless they do the same change).
 
 1.5.4 (2024-08-03)
 ------------------------------------------------------------------------
diff --git a/Configuration.md b/Configuration.md
index ed6e9b6f..c561ce0e 100644
--- a/Configuration.md
+++ b/Configuration.md
@@ -225,6 +225,11 @@ This can be configured with the following CVars:
 - `r_useCarmacksReverse` Use Z-Fail ("Carmack's Reverse") when rendering shadows (default `1`)
 - `r_useStencilOpSeparate` Use glStencilOpSeparate() (if available) when rendering shadow (default `1`)
 - `r_scaleMenusTo43` Render full-screen menus in 4:3 by adding black bars on the left/right if necessary (default `1`)
+- `r_supportNoSpecular` Allow using the "nospecular" parm of lights under certain circumstances. If set to:
+    - `0` "nospecular" will always be ignored, as it's the case in Vanilla Doom3
+    - `1` "nospecular" is always used, even in old maps where it changes what they look like
+    - `-1` (the default) "nospecular" is only used in (new) maps that explicitly enable it
+      by setting `"allow_nospecular" "1"` in the worldspawn, existing maps continue to ignore it
 - `r_glDebugContext` Enable OpenGL debug context and printing warnings/errors from the graphics driver.  
   Changing that CVar requires a `vid_restart` (or set it as startup argument)
 
diff --git a/neo/renderer/RenderWorld_demo.cpp b/neo/renderer/RenderWorld_demo.cpp
index db94772d..2149b61a 100644
--- a/neo/renderer/RenderWorld_demo.cpp
+++ b/neo/renderer/RenderWorld_demo.cpp
@@ -108,27 +108,41 @@ bool		idRenderWorldLocal::ProcessDemoCommand( idDemoFile *readDemo, renderView_t
 
 	switch( (demoCommand_t)dc ) {
 	case DC_LOADMAP:
+	{
 		// read the initial data
 		demoHeader_t	header;
 
 		readDemo->ReadInt( header.version );
+		// the internal version value got replaced by DS_VERSION at toplevel
+		// DG: bumped version to 5 for nospecular support, still support old demos though.
+		if ( header.version != 4 && header.version != 5 ) {
+			common->Error( "Demo version mismatch.\n" );
+		}
+
 		readDemo->ReadInt( header.sizeofRenderEntity );
 		readDemo->ReadInt( header.sizeofRenderLight );
+		// DG: set allowNoSpecular from demo, if it's v5 (otherwise default to false)
+		//     when loading a normal map, this is "allow_nospecular" in the worldspawn
+		int allowNoSpecular = 0;
+		if ( header.version == 5 ) {
+			readDemo->ReadInt( allowNoSpecular );
+		}
+
 		for ( int i = 0; i < 256; i++ )
 			readDemo->ReadChar( header.mapname[i] );
-		// the internal version value got replaced by DS_VERSION at toplevel
-		if ( header.version != 4 ) {
-				common->Error( "Demo version mismatch.\n" );
-		}
 
 		if ( r_showDemo.GetBool() ) {
 			common->Printf( "DC_LOADMAP: %s\n", header.mapname );
 		}
 		InitFromMap( header.mapname );
 
+		// DG: must be set after InitFromMap(), because that sets it to false as a default
+		tr.allowNoSpecular = (allowNoSpecular != 0);
+
 		newMap = true;		// we will need to set demoTimeOffset
 
 		break;
+	}
 
 	case DC_RENDERVIEW:
 		readDemo->ReadInt( renderView->viewID );
@@ -281,12 +295,13 @@ void	idRenderWorldLocal::WriteLoadMap() {
 	//     so it's good if the ones behind the actual name are *all* \0
 	strncpy( header.mapname, mapName.c_str(), sizeof( header.mapname ) - 1 );
 	header.mapname[sizeof( header.mapname ) - 1] = '\0'; // make sure the last chars is also \0
-	header.version = 4;
+	header.version = 5; // DG: bumped to 5 for nospecular support
 	header.sizeofRenderEntity = sizeof( renderEntity_t );
 	header.sizeofRenderLight = sizeof( renderLight_t );
 	session->writeDemo->WriteInt( header.version );
 	session->writeDemo->WriteInt( header.sizeofRenderEntity );
 	session->writeDemo->WriteInt( header.sizeofRenderLight );
+	session->writeDemo->WriteInt( tr.allowNoSpecular ); // DG: added for nospecular support
 	for ( int i = 0; i < 256; i++ )
 		session->writeDemo->WriteChar( header.mapname[i] );