diff --git a/stim/visualization/obj.h b/stim/visualization/obj.h
index dfc5235..033dfd5 100644
--- a/stim/visualization/obj.h
+++ b/stim/visualization/obj.h
@@ -614,7 +614,7 @@ public:
 
 		if (M.size()) {															//if materials are used
 			
-			outfile.open(mtl_filename);										//open the material file
+			outfile.open(mtl_filename.c_str());										//open the material file
 			for (size_t i = 0; i < M.size(); i++) {								//for each material
 				outfile << M[i].str() << std::endl;								//output the material name and properties
 			}
diff --git a/stim/visualization/obj/obj_material.h b/stim/visualization/obj/obj_material.h
index 3986a92..688f28a 100644
--- a/stim/visualization/obj/obj_material.h
+++ b/stim/visualization/obj/obj_material.h
@@ -2,6 +2,7 @@
 #define OBJ_MATERIAL_H
 
 #include <sstream>
+#include <cstring>
 
 namespace stim {
 
@@ -25,9 +26,9 @@ struct obj_material {
 	std::string tex_decal;		//stencil decal
 
 	obj_material() {			//constructor
-		memset(ka, 0, sizeof(T) * 3);
-		memset(kd, 0, sizeof(T) * 3);
-		memset(ks, 0, sizeof(T) * 3);
+		std::memset(ka, 0, sizeof(T) * 3);
+		std::memset(kd, 0, sizeof(T) * 3);
+		std::memset(ks, 0, sizeof(T) * 3);
 		ns = 10;
 		illum = 2;
 
--
libgit2 0.21.4