diff --git a/src/tools/vmap4_extractor/gameobject_extract.cpp b/src/tools/vmap4_extractor/gameobject_extract.cpp
index 206a901e4d..b4c15817b8 100644
--- a/src/tools/vmap4_extractor/gameobject_extract.cpp
+++ b/src/tools/vmap4_extractor/gameobject_extract.cpp
@@ -34,6 +34,8 @@ bool ExtractSingleModel(std::string& fname)
         fname.erase(fname.length() - 2, 2);
         fname.append("2");
     }
+    // >= 3.1.0 ADT MMDX section store filename.m2 filenames for corresponded .m2 file
+    // nothing do
 
     std::string originalName = fname;
 
@@ -59,7 +61,7 @@ extern HANDLE LocaleMpq;
 
 void ExtractGameobjectModels()
 {
-    printf("Extracting GameObject models...");
+    printf("Extracting GameObject models...\n");
     DBCFile dbc(LocaleMpq, "DBFilesClient\\GameObjectDisplayInfo.dbc");
     if (!dbc.open())
     {
@@ -89,13 +91,15 @@ void ExtractGameobjectModels()
             continue;
 
         FixNameCase((char*)path.c_str(), path.size());
-        char * name = GetPlainName((char*)path.c_str());
+        char* name = GetPlainName((char*)path.c_str());
         FixNameSpaces(name, strlen(name));
 
-        char * ch_ext = GetExtension(name);
+        char* ch_ext = GetExtension(name);
         if (!ch_ext)
             continue;
 
+        strToLower(ch_ext);
+
         bool result = false;
         uint8 isWmo = 0;
         if (!strcmp(ch_ext, ".wmo"))
@@ -103,8 +107,11 @@ void ExtractGameobjectModels()
             isWmo = 1;
             result = ExtractSingleWmo(path);
         }
-        else if (!strcmp(ch_ext, ".mdl"))   // TODO: extract .mdl files, if needed
+        else if (!strcmp(ch_ext, ".mdl"))
+        {
+            // TODO: extract .mdl files, if needed
             continue;
+        }
         else //if (!strcmp(ch_ext, ".mdx") || !strcmp(ch_ext, ".m2"))
             result = ExtractSingleModel(path);
 
diff --git a/src/tools/vmap4_extractor/vmapexport.cpp b/src/tools/vmap4_extractor/vmapexport.cpp
index a190f15fd8..7d45e06b8e 100644
--- a/src/tools/vmap4_extractor/vmapexport.cpp
+++ b/src/tools/vmap4_extractor/vmapexport.cpp
@@ -260,30 +260,13 @@ bool FileExists(char const* file)
     return false;
 }
 
-bool ExtractWmo()
+void strToLower(char* str)
 {
-    bool success = false;
-
-    //char const* ParsArchiveNames[] = {"patch-2.MPQ", "patch.MPQ", "common.MPQ", "expansion.MPQ"};
-
-    SFILE_FIND_DATA data;
-    HANDLE find = SFileFindFirstFile(WorldMpq, "*.wmo", &data, nullptr);
-    if (find != nullptr)
+    while (*str)
     {
-        do
-        {
-            std::string str = data.cFileName;
-            //printf("Extracting wmo %s\n", str.c_str());
-            success |= ExtractSingleWmo(str);
-        }
-        while (SFileFindNextFile(find, &data));
+        *str = tolower(*str);
+        ++str;
     }
-    SFileFindClose(find);
-
-    if (success)
-        printf("\nExtract wmo complete (No (fatal) errors)\n");
-
-    return success;
 }
 
 bool ExtractSingleWmo(std::string& fname)
@@ -344,6 +327,7 @@ bool ExtractSingleWmo(std::string& fname)
             char temp[1024];
             strncpy(temp, fname.c_str(), 1024);
             temp[fname.length()-4] = 0;
+
             char groupFileName[1024];
             sprintf(groupFileName, "%s_%03u.wmo", temp, i);
             //printf("Trying to open groupfile %s\n",groupFileName);
@@ -378,6 +362,7 @@ bool ExtractSingleWmo(std::string& fname)
 
     fseek(output, 8, SEEK_SET); // store the correct no of vertices
     fwrite(&Wmo_nVertices, sizeof(int), 1, output);
+    // store the correct no of groups
     fwrite(&groupCount, sizeof(uint32), 1, output);
     fclose(output);
 
diff --git a/src/tools/vmap4_extractor/vmapexport.h b/src/tools/vmap4_extractor/vmapexport.h
index 292690b53b..2f329477f9 100644
--- a/src/tools/vmap4_extractor/vmapexport.h
+++ b/src/tools/vmap4_extractor/vmapexport.h
@@ -36,6 +36,7 @@ extern std::unordered_map<std::string, WMODoodadData> WmoDoodads;
 uint32 GenerateUniqueObjectId(uint32 clientId, uint16 clientDoodadId);
 
 bool FileExists(const char * file);
+void strToLower(char* str);
 
 bool ExtractSingleWmo(std::string& fname);
 bool ExtractSingleModel(std::string& fname);