--- a/src/ai/ai_config.cpp
+++ b/src/ai/ai_config.cpp
@@ -17,7 +17,7 @@
 
 void AIConfig::ChangeAI(const char *name, int version, bool force_exact_match, bool is_random_ai)
 {
-	free((void *)this->name);
+	free(this->name);
 	this->name = (name == NULL) ? NULL : strdup(name);
 	this->info = (name == NULL) ? NULL : AI::FindInfo(this->name, version, force_exact_match);
 	this->version = (info == NULL) ? -1 : info->GetVersion();
@@ -31,7 +31,7 @@
 	int start_date = this->GetSetting("start_date");
 
 	for (SettingValueList::iterator it = this->settings.begin(); it != this->settings.end(); it++) {
-		free((void*)(*it).first);
+		free((*it).first);
 	}
 	this->settings.clear();
 
@@ -65,7 +65,7 @@
 
 AIConfig::~AIConfig()
 {
-	free((void *)this->name);
+	free(this->name);
 	this->ResetSettings();
 	if (this->config_list != NULL) delete this->config_list;
 }
@@ -148,7 +148,7 @@
 void AIConfig::ResetSettings()
 {
 	for (SettingValueList::iterator it = this->settings.begin(); it != this->settings.end(); it++) {
-		free((void*)(*it).first);
+		free((*it).first);
 	}
 	this->settings.clear();
 }

--- a/src/ai/ai_info.cpp
+++ b/src/ai/ai_info.cpp
@@ -39,7 +39,7 @@
 
 AILibrary::~AILibrary()
 {
-	free((void *)this->category);
+	free(this->category);
 }
 
 /* static */ SQInteger AIFileInfo::Constructor(HSQUIRRELVM vm, AIFileInfo *info)
@@ -146,8 +146,8 @@
 {
 	/* Free all allocated strings */
 	for (AIConfigItemList::iterator it = this->config_list.begin(); it != this->config_list.end(); it++) {
-		free((void*)(*it).name);
-		free((void*)(*it).description);
+		free((*it).name);
+		free((*it).description);
 		if (it->labels != NULL) {
 			for (LabelMapping::iterator it2 = (*it).labels->Begin(); it2 != (*it).labels->End(); it2++) {
 				free(it2->second);
@@ -156,7 +156,7 @@
 		}
 	}
 	this->config_list.clear();
-	free((void*)this->api_version);
+	free(this->api_version);
 }
 
 bool AIInfo::CanLoadFromVersion(int version) const

--- a/src/ai/ai_scanner.cpp
+++ b/src/ai/ai_scanner.cpp
@@ -68,16 +68,16 @@
 {
 	AIInfoList::iterator it = this->info_list.begin();
 	for (; it != this->info_list.end(); it++) {
-		free((void *)(*it).first);
+		free((*it).first);
 		delete (*it).second;
 	}
 	it = this->info_single_list.begin();
 	for (; it != this->info_single_list.end(); it++) {
-		free((void *)(*it).first);
+		free((*it).first);
 	}
 	AILibraryList::iterator lit = this->library_list.begin();
 	for (; lit != this->library_list.end(); lit++) {
-		free((void *)(*lit).first);
+		free((*lit).first);
 		delete (*lit).second;
 	}
 

--- a/src/ai/api/ai_controller.cpp
+++ b/src/ai/api/ai_controller.cpp
@@ -54,8 +54,8 @@
 AIController::~AIController()
 {
 	for (LoadedLibraryList::iterator iter = this->loaded_library.begin(); iter != this->loaded_library.end(); iter++) {
-		free((void *)(*iter).second);
-		free((void *)(*iter).first);
+		free((*iter).second);
+		free((*iter).first);
 	}
 
 	this->loaded_library.clear();

--- a/src/base_media_base.h
+++ b/src/base_media_base.h
@@ -70,16 +70,16 @@
 	/** Free everything we allocated */
 	~BaseSet()
 	{
-		free((void*)this->name);
+		free(this->name);
 
 		for (TranslatedStrings::iterator iter = this->description.Begin(); iter != this->description.End(); iter++) {
-			free((void*)iter->first);
-			free((void*)iter->second);
+			free(iter->first);
+			free(iter->second);
 		}
 
 		for (uint i = 0; i < NUM_FILES; i++) {
-			free((void*)this->files[i].filename);
-			free((void*)this->files[i].missing_warning);
+			free(this->files[i].filename);
+			free(this->files[i].missing_warning);
 		}
 
 		delete this->next;

--- a/src/blitter/32bpp_optimized.cpp
+++ b/src/blitter/32bpp_optimized.cpp
@@ -354,7 +354,7 @@
 		lengths[z][1] = (byte *)dst_n_ln  - (byte *)dst_n_orig[z];
 
 		free(src_orig->data);
-		free((void *)src_orig);
+		free(src_orig);
 	}
 
 	uint len = 0; // total length of data

--- a/src/blitter/factory.hpp
+++ b/src/blitter/factory.hpp
@@ -78,7 +78,7 @@
 		if (this->name == NULL) return;
 		GetBlitters().erase(this->name);
 		if (GetBlitters().empty()) delete &GetBlitters();
-		free((void *)this->name);
+		free(this->name);
 	}
 
 	/**

--- a/src/depend/depend.cpp
+++ b/src/depend/depend.cpp
@@ -30,6 +30,15 @@
 #include <set>
 #include <stack>
 
+/**
+ * Version of the standard free that accepts const pointers.
+ * @param ptr The data to free.
+ */
+static inline void free(const void *ptr)
+{
+	free(const_cast<void *>(ptr));
+}
+
 #ifndef PATH_MAX
 /** The maximum length of paths, if we don't know it. */
 #	define PATH_MAX 260
@@ -672,7 +681,7 @@
 										}
 									}
 									if (curfile->second->find(h) == curfile->second->end()) curfile->second->insert(strdup(h));
-									free((void*)h);
+									free(h);
 								}
 							}
 							/* FALL THROUGH */
@@ -705,7 +714,7 @@
 							}
 							StringSet::iterator it = defines.find(lexer.GetString());
 							if (it != defines.end()) {
-								free((void*)*it);
+								free(*it);
 								defines.erase(it);
 							}
 							lexer.Lex();
@@ -808,7 +817,7 @@
 
 	if (!header) {
 		for (StringSet::iterator it = defines.begin(); it != defines.end(); it++) {
-			free((void*)*it);
+			free(*it);
 		}
 		defines.clear();
 		while (!ignore.empty()) ignore.pop();
@@ -940,31 +949,31 @@
 
 	for (StringMap::iterator it = _files.begin(); it != _files.end(); it++) {
 		for (StringSet::iterator h = it->second->begin(); h != it->second->end(); h++) {
-			free((void*)*h);
+			free(*h);
 		}
 		it->second->clear();
 		delete it->second;
-		free((void*)it->first);
+		free(it->first);
 	}
 	_files.clear();
 
 	for (StringMap::iterator it = _headers.begin(); it != _headers.end(); it++) {
 		for (StringSet::iterator h = it->second->begin(); h != it->second->end(); h++) {
-			free((void*)*h);
+			free(*h);
 		}
 		it->second->clear();
 		delete it->second;
-		free((void*)it->first);
+		free(it->first);
 	}
 	_headers.clear();
 
 	for (StringSet::iterator it = _defines.begin(); it != _defines.end(); it++) {
-		free((void*)*it);
+		free(*it);
 	}
 	_defines.clear();
 
 	for (StringSet::iterator it = _include_dirs.begin(); it != _include_dirs.end(); it++) {
-		free((void*)*it);
+		free(*it);
 	}
 	_include_dirs.clear();
 

--- a/src/driver.cpp
+++ b/src/driver.cpp
@@ -236,8 +236,8 @@
 	const char *longname = (*it).first;
 
 	GetDrivers().erase(it);
-	free((void *)longname);
+	free(longname);
 
 	if (GetDrivers().empty()) delete &GetDrivers();
-	free((void *)this->name);
+	free(this->name);
 }

--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -1175,7 +1175,7 @@
 	/* If we don't have networking, we don't need to make the directory. But
 	 * if it exists we keep it, otherwise remove it from the search paths. */
 	if (!FileExists(_searchpaths[SP_AUTODOWNLOAD_DIR]))  {
-		free((void*)_searchpaths[SP_AUTODOWNLOAD_DIR]);
+		free(_searchpaths[SP_AUTODOWNLOAD_DIR]);
 		_searchpaths[SP_AUTODOWNLOAD_DIR] = NULL;
 	}
 #endif /* ENABLE_NETWORK */

--- a/src/network/core/tcp_http.cpp
+++ b/src/network/core/tcp_http.cpp
@@ -73,7 +73,7 @@
 
 	if (this->sock != INVALID_SOCKET) closesocket(this->sock);
 	this->sock = INVALID_SOCKET;
-	free((void*)this->data);
+	free(this->data);
 }
 
 NetworkRecvStatus NetworkHTTPSocketHandler::CloseConnection(bool error)

--- a/src/network/core/tcp_http.h
+++ b/src/network/core/tcp_http.h
@@ -105,13 +105,13 @@
 	/** Free all our allocated data. */
 	~NetworkHTTPContentConnecter()
 	{
-		free((void*)this->url);
+		free(this->url);
 	}
 
 	virtual void OnFailure()
 	{
 		this->callback->OnFailure();
-		free((void*)this->data);
+		free(this->data);
 	}
 
 	virtual void OnConnect(SOCKET s)

--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -3071,10 +3071,10 @@
 	if (HasBit(ind->cleanup_flag, CLEAN_TILELAYOUT) && ind->table != NULL) {
 		for (int j = 0; j < ind->num_table; j++) {
 			/* remove the individual layouts */
-			free((void*)ind->table[j]);
+			free(ind->table[j]);
 		}
 		/* remove the layouts pointers */
-		free((void*)ind->table);
+		free(ind->table);
 		ind->table = NULL;
 	}
 }
@@ -3322,7 +3322,7 @@
 				}
 
 				if (HasBit(indsp->cleanup_flag, CLEAN_RANDOMSOUNDS)) {
-					free((void*)indsp->random_sounds);
+					free(indsp->random_sounds);
 				}
 				indsp->random_sounds = sounds;
 				SetBit(indsp->cleanup_flag, CLEAN_RANDOMSOUNDS);
@@ -7663,10 +7663,10 @@
 					/* We need to remove the tiles layouts */
 					for (int j = 0; j < as->num_table; j++) {
 						/* remove the individual layouts */
-						free((void*)as->table[j]);
+						free(as->table[j]);
 					}
-					free((void*)as->table);
-					free((void*)as->depot_table);
+					free(as->table);
+					free(as->depot_table);
 
 					free(as);
 				}
@@ -7703,7 +7703,7 @@
 
 				/* We need to remove the sounds array */
 				if (HasBit(ind->cleanup_flag, CLEAN_RANDOMSOUNDS)) {
-					free((void*)ind->random_sounds);
+					free(ind->random_sounds);
 				}
 
 				/* We need to remove the tiles layouts */

--- a/src/newgrf_commons.h
+++ b/src/newgrf_commons.h
@@ -140,8 +140,8 @@
 
 	virtual ~NewGRFSpriteLayout()
 	{
-		free(const_cast<DrawTileSeqStruct*>(this->seq));
-		free(const_cast<TileLayoutRegisters*>(this->registers));
+		free(this->seq);
+		free(this->registers);
 	}
 
 	/**

--- a/src/newgrf_spritegroup.cpp
+++ b/src/newgrf_spritegroup.cpp
@@ -20,8 +20,8 @@
 
 RealSpriteGroup::~RealSpriteGroup()
 {
-	free((void*)this->loaded);
-	free((void*)this->loading);
+	free(this->loaded);
+	free(this->loading);
 }
 
 DeterministicSpriteGroup::~DeterministicSpriteGroup()
@@ -32,7 +32,7 @@
 
 RandomizedSpriteGroup::~RandomizedSpriteGroup()
 {
-	free((void*)this->groups);
+	free(this->groups);
 }
 
 TemporaryStorageArray<int32, 0x110> _temp_store;

--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -806,9 +806,9 @@
 	/* Reset windowing system, stop drivers, free used memory, ... */
 	ShutdownGame();
 
-	free(const_cast<char *>(BaseGraphics::ini_set));
-	free(const_cast<char *>(BaseSounds::ini_set));
-	free(const_cast<char *>(BaseMusic::ini_set));
+	free(BaseGraphics::ini_set);
+	free(BaseSounds::ini_set);
+	free(BaseMusic::ini_set);
 	free(_ini_musicdriver);
 	free(_ini_sounddriver);
 	free(_ini_videodriver);

--- a/src/querystring_gui.h
+++ b/src/querystring_gui.h
@@ -48,7 +48,7 @@
 	 */
 	~QueryString()
 	{
-		free((void*)this->orig);
+		free(this->orig);
 	}
 
 private:

--- a/src/script/script_info.cpp
+++ b/src/script/script_info.cpp
@@ -23,13 +23,13 @@
 
 ScriptFileInfo::~ScriptFileInfo()
 {
-	free((void *)this->author);
-	free((void *)this->name);
-	free((void *)this->short_name);
-	free((void *)this->description);
-	free((void *)this->date);
-	free((void *)this->instance_name);
-	free((void *)this->url);
+	free(this->author);
+	free(this->name);
+	free(this->short_name);
+	free(this->description);
+	free(this->date);
+	free(this->instance_name);
+	free(this->url);
 	free(this->main_script);
 	free(this->tar_file);
 	free(this->SQ_instance);

--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -448,7 +448,7 @@
 		if (_game_mode == GM_MENU) {
 			const char *name = T::GetSet(index)->name;
 
-			free(const_cast<char *>(T::ini_set));
+			free(T::ini_set);
 			T::ini_set = strdup(name);
 
 			T::SetSet(name);

--- a/src/stdafx.h
+++ b/src/stdafx.h
@@ -438,6 +438,15 @@
 #endif
 
 /**
+ * Version of the standard free that accepts const pointers.
+ * @param ptr The data to free.
+ */
+static FORCEINLINE void free(const void *ptr)
+{
+	free(const_cast<void *>(ptr));
+}
+
+/**
  * The largest value that can be entered in a variable
  * @param type the type of the variable
  */

--- a/src/tar_type.h
+++ b/src/tar_type.h
@@ -24,7 +24,7 @@
 	 * to free filename, which isn't set at that moment... but because it
 	 * initializes the variable with garbage, it's going to segfault. */
 	TarListEntry() : filename(NULL), dirname(NULL) {}
-	~TarListEntry() { free((void*)this->filename); free((void*)this->dirname); }
+	~TarListEntry() { free(this->filename); free(this->dirname); }
 };
 
 struct TarFileListEntry {