diff --git a/src/mod_converter/model.cpp b/src/mod_converter/model.cpp
index d646441..d5f367a 100644
--- a/src/mod_converter/model.cpp
+++ b/src/mod_converter/model.cpp
@@ -187,10 +187,13 @@ std::string vertex::printVertex(bool rotate_x_90) const
     return s;
 }
 
-std::string vertex::printNormal() const
+std::string vertex::printNormal(bool rotate_x_90) const
 {
     string s;
-    s = "vn " + to_string(-normal.x) + " " + to_string(normal.y) + " " + to_string(-normal.z);
+    if (rotate_x_90)
+        s = "vn " + to_string(-normal.x) + " " + to_string(-normal.z) + " " + to_string(normal.y);
+    else
+        s = "vn " + to_string(-normal.x) + " " + to_string(normal.y) + " " + to_string(-normal.z);
     return s;
 }
 
@@ -305,7 +308,7 @@ std::string block::printObj(int group_offset, bool rotate_x_90) const
         s += v.printVertex(rotate_x_90) + "\n";
     s += "\n";
     for (auto &v : vertices)
-        s += v.printNormal() + "\n";
+        s += v.printNormal(rotate_x_90) + "\n";
     s += "\n";
     for (auto &v : vertices)
         s += v.printTex() + "\n";
diff --git a/src/mod_converter/model.h b/src/mod_converter/model.h
index 51dcb17..a4a2a63 100644
--- a/src/mod_converter/model.h
+++ b/src/mod_converter/model.h
@@ -98,7 +98,7 @@ struct vertex
     void load(const buffer &b, uint32_t flags);
 
     std::string printVertex(bool rotate_x_90 = false) const;
-    std::string printNormal() const;
+    std::string printNormal(bool rotate_x_90 = false) const;
     std::string printTex() const;
 };