diff --git a/src/Cube.mm b/src/Cube.mm
index 6621caa..a91d05c 100644
--- a/src/Cube.mm
+++ b/src/Cube.mm
@@ -135,37 +135,37 @@ VARP(minmillis, 0, 5, 1000);
 	log(@"basetex");
 	int xs, ys;
 	if (!installtex(2,
-	        [_userDataIRI IRIByAppendingPathComponent:@"data/newchars.png"],
+	        [_gameDataIRI IRIByAppendingPathComponent:@"data/newchars.png"],
 	        &xs, &ys, false) ||
 	    !installtex(3,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/martin/base.png"],
 	        &xs, &ys, false) ||
 	    !installtex(6,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/martin/ball1.png"],
 	        &xs, &ys, false) ||
 	    !installtex(7,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/martin/smoke.png"],
 	        &xs, &ys, false) ||
 	    !installtex(8,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/martin/ball2.png"],
 	        &xs, &ys, false) ||
 	    !installtex(9,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/martin/ball3.png"],
 	        &xs, &ys, false) ||
 	    !installtex(4,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/explosion.jpg"],
 	        &xs, &ys, false) ||
 	    !installtex(5,
-	        [_userDataIRI IRIByAppendingPathComponent:@"data/items.png"],
+	        [_gameDataIRI IRIByAppendingPathComponent:@"data/items.png"],
 	        &xs, &ys, false) ||
 	    !installtex(1,
-	        [_userDataIRI
+	        [_gameDataIRI
 	            IRIByAppendingPathComponent:@"data/crosshair.png"],
 	        &xs, &ys, false))
 		fatal(@"could not find core textures (hint: run cube from the "
@@ -182,8 +182,9 @@ VARP(minmillis, 0, 5, 1000);
 	exec(@"data/prefabs.cfg");
 	exec(@"data/sounds.cfg");
 	exec(@"servers.cfg");
-	if (!execfile(@"config.cfg"))
-		execfile(@"data/defaults.cfg");
+	if (!execfile([_userDataIRI IRIByAppendingPathComponent:@"config.cfg"]))
+		execfile([_gameDataIRI
+		    IRIByAppendingPathComponent:@"data/defaults.cfg"]);
 	exec(@"autoexec.cfg");
 
 	log(@"localconnect");
diff --git a/src/commands.mm b/src/commands.mm
index 0ff794a..914074f 100644
--- a/src/commands.mm
+++ b/src/commands.mm
@@ -338,13 +338,15 @@ complete(OFString *s_)
 }
 
 bool
-execfile(OFString *cfgfile)
+execfile(OFIRI *cfgfile)
 {
 	@autoreleasepool {
 		OFString *command;
 		@try {
-			command = [OFString stringWithContentsOfFile:cfgfile];
-		} @catch (id e) {
+			command = [OFString stringWithContentsOfIRI:cfgfile];
+		} @catch (OFOpenItemFailedException *e) {
+			return false;
+		} @catch (OFReadFailedException *e) {
 			return false;
 		}
 
@@ -356,10 +358,12 @@ execfile(OFString *cfgfile)
 void
 exec(OFString *cfgfile)
 {
-	if (!execfile(cfgfile)) {
-		@autoreleasepool {
+	@autoreleasepool {
+		if (!execfile([Cube.sharedInstance.userDataIRI
+		        IRIByAppendingPathComponent:cfgfile]) &&
+		    !execfile([Cube.sharedInstance.gameDataIRI
+		        IRIByAppendingPathComponent:cfgfile]))
 			conoutf(@"could not read \"%@\"", cfgfile);
-		}
 	}
 }
 
diff --git a/src/protos.h b/src/protos.h
index 441dae7..e9f2ff5 100644
--- a/src/protos.h
+++ b/src/protos.h
@@ -9,7 +9,7 @@ extern bool identexists(OFString *name);
 extern bool addcommand(OFString *name, void (*fun)(), int narg);
 extern int execute(OFString *p, bool down = true);
 extern void exec(OFString *cfgfile);
-extern bool execfile(OFString *cfgfile);
+extern bool execfile(OFIRI *cfgfile);
 extern void resetcomplete();
 extern void complete(OFString *s);
 extern void alias(OFString *name, OFString *action);
diff --git a/src/worldio.mm b/src/worldio.mm
index dc9f70b..78cf767 100644
--- a/src/worldio.mm
+++ b/src/worldio.mm
@@ -384,8 +384,10 @@ load_world(OFString *mname) // still supports all map formats that have existed
 			if (identexists(aliasname))
 				alias(aliasname, @"");
 		}
-		execfile(@"data/default_map_settings.cfg");
-		execfile(pcfname);
-		execfile(mcfname);
+		OFIRI *gameDataIRI = Cube.sharedInstance.gameDataIRI;
+		execfile([gameDataIRI IRIByAppendingPathComponent:
+		                          @"data/default_map_settings.cfg"]);
+		execfile([gameDataIRI IRIByAppendingPathComponent:pcfname]);
+		execfile([gameDataIRI IRIByAppendingPathComponent:mcfname]);
 	}
 }