diff --git a/src/os/macosx/osx_stdafx.h b/src/os/macosx/osx_stdafx.h
index 476362cccd..d90a19c5f7 100644
--- a/src/os/macosx/osx_stdafx.h
+++ b/src/os/macosx/osx_stdafx.h
@@ -18,6 +18,10 @@
 #define HAVE_OSX_107_SDK
 #endif
 
+#ifdef MAC_OS_X_VERSION_10_9
+#define HAVE_OSX_109_SDK
+#endif
+
 #ifdef MAC_OS_X_VERSION_10_11
 #define HAVE_OSX_1011_SDK
 #endif
diff --git a/src/os/macosx/string_osx.cpp b/src/os/macosx/string_osx.cpp
index 63be4d3ad9..ad4983e9aa 100644
--- a/src/os/macosx/string_osx.cpp
+++ b/src/os/macosx/string_osx.cpp
@@ -19,6 +19,35 @@
 
 
 #if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
+
+/* CTRunDelegateCreate is supported since MacOS X 10.5, but was only included in the SDKs starting with the 10.9 SDK. */
+#ifndef HAVE_OSX_109_SDK
+extern "C" {
+	typedef const struct __CTRunDelegate * CTRunDelegateRef;
+
+	typedef void (*CTRunDelegateDeallocateCallback) (void* refCon);
+	typedef CGFloat (*CTRunDelegateGetAscentCallback) (void* refCon);
+	typedef CGFloat (*CTRunDelegateGetDescentCallback) (void* refCon);
+	typedef CGFloat (*CTRunDelegateGetWidthCallback) (void* refCon);
+	typedef struct {
+		CFIndex                         version;
+		CTRunDelegateDeallocateCallback dealloc;
+		CTRunDelegateGetAscentCallback  getAscent;
+		CTRunDelegateGetDescentCallback getDescent;
+		CTRunDelegateGetWidthCallback   getWidth;
+	} CTRunDelegateCallbacks;
+
+	enum {
+		kCTRunDelegateVersion1 = 1,
+		kCTRunDelegateCurrentVersion = kCTRunDelegateVersion1
+	};
+
+	extern const CFStringRef kCTRunDelegateAttributeName AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER;
+
+	CTRunDelegateRef CTRunDelegateCreate(const CTRunDelegateCallbacks* callbacks, void* refCon) AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER;
+}
+#endif /* HAVE_OSX_109_SDK */
+
 /** Cached current locale. */
 static CFAutoRelease<CFLocaleRef> _osx_locale;
 /** CoreText cache for font information, cleared when OTTD changes fonts. */