diff --git a/src/RageFileManager.cpp b/src/RageFileManager.cpp
index 0a13efffbc..80db4a8779 100644
--- a/src/RageFileManager.cpp
+++ b/src/RageFileManager.cpp
@@ -414,7 +414,7 @@ static void ChangeToDirOfExecutable( const RString &argv0 )
 	 * through a symlink. Assume this is the case and change to the dir of the symlink. */
 	if( Basename(RageFileManagerUtil::sDirOfExecutable) == "MacOS" )
 		CollapsePath( RageFileManagerUtil::sDirOfExecutable += "/../../../" );
-	if( chdir( RageFileManagerUtil::sDirOfExecutable ) )
+	if( chdir( RageFileManagerUtil::sDirOfExecutable.c_str() ) )
 #endif
 	{
 		LOG->Warn("Can't set current working directory to %s", RageFileManagerUtil::sDirOfExecutable.c_str());
diff --git a/src/RageUtil_CharConversions.cpp b/src/RageUtil_CharConversions.cpp
index 0f63aaeb1d..739cfa3984 100644
--- a/src/RageUtil_CharConversions.cpp
+++ b/src/RageUtil_CharConversions.cpp
@@ -99,7 +99,7 @@ static bool ConvertFromCP( RString &sText, int iCodePage )
 	if( encoding == kCFStringEncodingInvalidId )
 		return false;
 
-	CFStringRef old = CFStringCreateWithCString( kCFAllocatorDefault, sText, encoding );
+	CFStringRef old = CFStringCreateWithCString( kCFAllocatorDefault, sText.c_str(), encoding );
 
 	if( old == nullptr )
 		return false;
diff --git a/src/arch/Dialog/DialogDriver_MacOSX.cpp b/src/arch/Dialog/DialogDriver_MacOSX.cpp
index b227f83e47..cb902f14f3 100644
--- a/src/arch/Dialog/DialogDriver_MacOSX.cpp
+++ b/src/arch/Dialog/DialogDriver_MacOSX.cpp
@@ -46,7 +46,7 @@ void DialogDriver_MacOSX::OK( RString sMessage, RString sID )
 {
 	CFBundleRef bundle = CFBundleGetMainBundle();
 	CFStringRef sDSA = LSTRING( bundle, "Don't show again" );
-	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, CFSTR("OK"), sDSA );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage.c_str(), CFSTR("OK"), sDSA );
 
 	CFRelease( sDSA );
 	if( result == kCFUserNotificationAlternateResponse )
@@ -55,7 +55,7 @@ void DialogDriver_MacOSX::OK( RString sMessage, RString sID )
 
 void DialogDriver_MacOSX::Error( RString sError, RString sID )
 {
-	ShowAlert( kCFUserNotificationStopAlertLevel, sError, CFSTR("OK") );
+	ShowAlert( kCFUserNotificationStopAlertLevel, sError.c_str(), CFSTR("OK") );
 }
 
 Dialog::Result DialogDriver_MacOSX::OKCancel( RString sMessage, RString sID )
@@ -63,7 +63,7 @@ Dialog::Result DialogDriver_MacOSX::OKCancel( RString sMessage, RString sID )
 	CFBundleRef bundle = CFBundleGetMainBundle();
 	CFStringRef sOK = LSTRING( bundle, "OK" );
 	CFStringRef sCancel = LSTRING( bundle, "Cancel" );
-	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sOK, sCancel );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage.c_str(), sOK, sCancel );
 
 	CFRelease( sOK );
 	CFRelease( sCancel );
@@ -85,7 +85,7 @@ Dialog::Result DialogDriver_MacOSX::AbortRetryIgnore( RString sMessage, RString
 	CFStringRef sIgnore = LSTRING( bundle, "Ignore" );
 	CFStringRef sRetry = LSTRING( bundle, "Retry" );
 	CFStringRef sAbort = LSTRING( bundle, "Abort" );
-	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sIgnore, sRetry, sAbort );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage.c_str(), sIgnore, sRetry, sAbort );
 
 	CFRelease( sIgnore );
 	CFRelease( sRetry );
@@ -110,7 +110,7 @@ Dialog::Result DialogDriver_MacOSX::AbortRetry( RString sMessage, RString sID )
 	CFBundleRef bundle = CFBundleGetMainBundle();
 	CFStringRef sRetry = LSTRING( bundle, "Retry" );
 	CFStringRef sAbort = LSTRING( bundle, "Abort" );
-	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sRetry, sAbort );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage.c_str(), sRetry, sAbort );
 
 	CFRelease( sRetry );
 	CFRelease( sAbort );
@@ -131,7 +131,7 @@ Dialog::Result DialogDriver_MacOSX::YesNo( RString sMessage, RString sID )
 	CFBundleRef bundle = CFBundleGetMainBundle();
 	CFStringRef sYes = LSTRING( bundle, "Yes" );
 	CFStringRef sNo = LSTRING( bundle, "No" );
-	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage, sYes, sNo );
+	CFOptionFlags result = ShowAlert( kCFUserNotificationNoteAlertLevel, sMessage.c_str(), sYes, sNo );
 
 	CFRelease( sYes );
 	CFRelease( sNo );
diff --git a/src/arch/LowLevelWindow/LowLevelWindow_MacOSX.mm b/src/arch/LowLevelWindow/LowLevelWindow_MacOSX.mm
index 35c990fdb4..47aaf916fd 100644
--- a/src/arch/LowLevelWindow/LowLevelWindow_MacOSX.mm
+++ b/src/arch/LowLevelWindow/LowLevelWindow_MacOSX.mm
@@ -325,7 +325,7 @@ void *LowLevelWindow_MacOSX::GetProcAddress( RString s )
 {
 	// http://developer.apple.com/qa/qa2001/qa1188.html
 	// Both functions mentioned in there are deprecated in 10.4.
-	const RString& symbolName( '_' + s );
+	const RString& symbolName( '_' + s.c_str() );
 	const uint32_t count = _dyld_image_count();
 	NSSymbol symbol = nil;
 	const uint32_t options = NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR;
diff --git a/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp b/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
index f18e5fd116..0a29ea3df7 100644
--- a/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
+++ b/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
@@ -160,7 +160,7 @@ void MemoryCardDriverThreaded_MacOSX::GetUSBStorageDevices( std::vector<UsbStora
 		// Now that we have the disk name, look up the IOServices associated with it.
 		CFMutableDictionaryRef dict;
 
-		if( !(dict = IOBSDNameMatching(kIOMasterPortDefault, 0, sDisk)) )
+		if( !(dict = IOBSDNameMatching(kIOMasterPortDefault, 0, sDisk.c_str())) )
 			continue;
 
 		// Look for certain properties: Leaf, Ejectable, Writable.
@@ -229,7 +229,7 @@ void MemoryCardDriverThreaded_MacOSX::GetUSBStorageDevices( std::vector<UsbStora
 
 bool MemoryCardDriverThreaded_MacOSX::TestWrite( UsbStorageDevice *pDevice )
 {
-	if( access(pDevice->sOsMountDir, W_OK) )
+	if( access(pDevice->sOsMountDir.c_str(), W_OK) )
 	{
 		pDevice->SetError( "TestFailed" );
 		return false;
diff --git a/src/archutils/Darwin/Crash.h b/src/archutils/Darwin/Crash.h
index 8dcd37f66c..e6f6f68db3 100644
--- a/src/archutils/Darwin/Crash.h
+++ b/src/archutils/Darwin/Crash.h
@@ -1,10 +1,11 @@
 #ifndef DARWIN_CRASH_H
 #define DARWIN_CRASH_H
+#include <string>
 
 namespace CrashHandler
 {
-	RString GetLogsDirectory();
-	void InformUserOfCrash( const RString& sPath );
+	std::string GetLogsDirectory();
+	void InformUserOfCrash( const std::string& sPath );
 	bool IsDebuggerPresent();
 	void DebugBreak();
 }
diff --git a/src/archutils/Darwin/Crash.mm b/src/archutils/Darwin/Crash.mm
index e00d718176..565622a5ae 100644
--- a/src/archutils/Darwin/Crash.mm
+++ b/src/archutils/Darwin/Crash.mm
@@ -4,6 +4,7 @@
 #include "arch/ArchHooks/ArchHooks.h"
 
 #include <cstddef>
+#include <string>
 
 #include <CoreServices/CoreServices.h>
 #include <os/log.h>
@@ -15,20 +16,21 @@
 
 #import <Foundation/Foundation.h>
 
-RString CrashHandler::GetLogsDirectory()
+std::string CrashHandler::GetLogsDirectory()
 {
 	NSFileManager *fileManager = [NSFileManager defaultManager];
 	NSURL *url = [fileManager URLForDirectory:NSLibraryDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
 	if (url == nil)
 		return "/tmp";
 
-	return RString([url fileSystemRepresentation]) + "/Logs/" PRODUCT_ID;
+	RString path= RString([url fileSystemRepresentation]) + "/Logs/" PRODUCT_ID;
+	return std::string(path.c_str());
 }
 
 // XXX Can we use LocalizedString here instead?
 #define LSTRING(b,x) CFBundleCopyLocalizedString( (b), CFSTR(x), nullptr, CFSTR("Localizable") )
 
-void CrashHandler::InformUserOfCrash( const RString& sPath )
+void CrashHandler::InformUserOfCrash( const std::string& sPath )
 {
 	CFBundleRef bundle = CFBundleGetMainBundle();
 	CFStringRef sAlternate = LSTRING( bundle, "Quit " PRODUCT_FAMILY );
diff --git a/src/archutils/Darwin/DarwinThreadHelpers.cpp b/src/archutils/Darwin/DarwinThreadHelpers.cpp
index e3cb341fc5..6e65114d9e 100644
--- a/src/archutils/Darwin/DarwinThreadHelpers.cpp
+++ b/src/archutils/Darwin/DarwinThreadHelpers.cpp
@@ -59,7 +59,7 @@ bool GetThreadBacktraceContext( uint64_t iID, BacktraceContext *ctx )
 #endif
 }
 
-RString SetThreadPrecedence( float prec )
+const char* SetThreadPrecedence( float prec )
 {
 	// Real values are between 0 and 63.
 	DEBUG_ASSERT( 0.0f <= prec && prec <= 1.0f );
@@ -69,7 +69,7 @@ RString SetThreadPrecedence( float prec )
 
 	if( ret != KERN_SUCCESS )
 		return mach_error_string( ret );
-	return RString();
+	return "";
 }
 
 /*
diff --git a/src/archutils/Darwin/DarwinThreadHelpers.h b/src/archutils/Darwin/DarwinThreadHelpers.h
index 403bfa93b4..48e0d37c58 100644
--- a/src/archutils/Darwin/DarwinThreadHelpers.h
+++ b/src/archutils/Darwin/DarwinThreadHelpers.h
@@ -23,7 +23,7 @@ uint64_t GetCurrentThreadId();
  * Valid values for the thread are from 0.0f to 1.0f.
  * 0.5f is the default.
  * @param prec the precedence to set. */
-RString SetThreadPrecedence( float prec );
+const char* SetThreadPrecedence( float prec );
 
 #endif
 
diff --git a/src/archutils/Darwin/HIDDevice.h b/src/archutils/Darwin/HIDDevice.h
index 204c4ab4a1..ccea51e042 100644
--- a/src/archutils/Darwin/HIDDevice.h
+++ b/src/archutils/Darwin/HIDDevice.h
@@ -9,6 +9,7 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
+#include <string>
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <IOKit/hid/IOHIDLib.h>
@@ -72,7 +73,7 @@ private:
 	IOHIDDeviceInterface **m_Interface;
 	IOHIDQueueInterface **m_Queue;
 	bool m_bRunning;
-	RString m_sDescription;
+	std::string m_sDescription;
 
 	static void AddLogicalDevice( const void *value, void *context );
 	static void AddElement( const void *value, void *context );
@@ -112,7 +113,7 @@ public:
 
 	bool Open( io_object_t device );
 	void StartQueue( CFRunLoopRef loopRef, IOHIDCallbackFunction callback, void *target );
-	inline const RString& GetDescription() const { return m_sDescription; }
+	inline const std::string& GetDescription() const { return m_sDescription; }
 
 	/* Add button presses (or releases) to vPresses for the given cookie. More
 	 * than one DeviceInput can be added at a time. For example, Two axes
diff --git a/src/archutils/Darwin/SpecialDirs.h b/src/archutils/Darwin/SpecialDirs.h
index d4576e1241..7e3d58abee 100644
--- a/src/archutils/Darwin/SpecialDirs.h
+++ b/src/archutils/Darwin/SpecialDirs.h
@@ -1,9 +1,11 @@
 #ifndef SPECIAL_DIRS_H
 #define SPECIAL_DIRS_H
 
+#include <string>
+
 namespace SpecialDirs
 {
-	RString GetDesktopDir();
+	std::string GetDesktopDir();
 };
 
 #endif
diff --git a/src/archutils/Darwin/SpecialDirs.mm b/src/archutils/Darwin/SpecialDirs.mm
index f013747cac..b8c3fcbc33 100644
--- a/src/archutils/Darwin/SpecialDirs.mm
+++ b/src/archutils/Darwin/SpecialDirs.mm
@@ -2,16 +2,18 @@
 #include "SpecialDirs.h"
 #include "ProductInfo.h"
 
+#include <string>
+
 #import <Foundation/Foundation.h>
 
-RString SpecialDirs::GetDesktopDir()
+std::string SpecialDirs::GetDesktopDir()
 {
 	NSFileManager *fileManager = [NSFileManager defaultManager];
 	NSURL *url = [fileManager URLForDirectory:NSDesktopDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
 	if (url == nil)
 		return "/tmp";
 
-	return RString([url fileSystemRepresentation]) + "/" PRODUCT_ID;
+	return std::string([url fileSystemRepresentation]) + "/" PRODUCT_ID;
 }