diff --git a/build/osx/wx.xcconfig b/build/osx/wx.xcconfig
index 3a3822f70e..11fb9bc93b 100644
--- a/build/osx/wx.xcconfig
+++ b/build/osx/wx.xcconfig
@@ -13,6 +13,6 @@ GCC_PRECOMPILE_PREFIX_HEADER = YES
 HEADER_SEARCH_PATHS = "$(WXROOT)/src/tiff/libtiff"
 USER_HEADER_SEARCH_PATHS = "$(WXROOT)/include" "$(WXROOT)/build/osx/setup/$(WXTOOLKIT)/include" "$(WXROOT)/src/zlib" "$(WXROOT)/src/jpeg" "$(WXROOT)/src/png" "$(WXROOT)/src/regex" "$(WXROOT)/src/expat/lib" "$(WXROOT)/src/tiff/libtiff" "$(WXROOT)/src/stc/scintilla/src" "$(WXROOT)/src/stc/scintilla/include" "$(WXROOT)/src/stc/scintilla/lexlib"
 ALWAYS_SEARCH_USER_PATHS = NO
-GCC_PREPROCESSOR_DEFINITIONS = $(WX_PREPROCESSOR_DEFINITIONS) WXBUILDING $(WXPLATFORM) __WX__ wxUSE_BASE=1 _FILE_OFFSET_BITS=64 _LARGE_FILES MACOS_CLASSIC __WXMAC_XCODE__=1 SCI_LEXER WX_PRECOMP=1 wxUSE_UNICODE_UTF8=0 wxUSE_UNICODE_WCHAR=1
+GCC_PREPROCESSOR_DEFINITIONS = $(WX_PREPROCESSOR_DEFINITIONS) WXBUILDING $(WXPLATFORM) __WX__ _FILE_OFFSET_BITS=64 _LARGE_FILES MACOS_CLASSIC __WXMAC_XCODE__=1 SCI_LEXER WX_PRECOMP=1 wxUSE_UNICODE_UTF8=0 wxUSE_UNICODE_WCHAR=1
 GCC_PFE_FILE_C_DIALECTS = c++ objective-c++
 GCC_C_LANGUAGE_STANDARD = gnu99
diff --git a/build/osx/wxcarbon_in.xcodeproj/project.pbxproj b/build/osx/wxcarbon_in.xcodeproj/project.pbxproj
index 1cc9e57e10..c0c3eb06f2 100644
--- a/build/osx/wxcarbon_in.xcodeproj/project.pbxproj
+++ b/build/osx/wxcarbon_in.xcodeproj/project.pbxproj
@@ -186,6 +186,11 @@
 			baseConfigurationReference = 40E3507E10EF2C130029DC34 /* wxcarbon.xcconfig */;
 			buildSettings = {
 				EXECUTABLE_PREFIX = lib;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					WXMAKINGDLL,
+					"wxUSE_BASE=1",
+				);
 				INSTALL_PATH = "@executable_path/../Frameworks/";
 				OTHER_LDFLAGS = "$(OTHER_LDFLAGS)";
 			};
@@ -196,6 +201,11 @@
 			baseConfigurationReference = 40E3507E10EF2C130029DC34 /* wxcarbon.xcconfig */;
 			buildSettings = {
 				EXECUTABLE_PREFIX = lib;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					WXMAKINGDLL,
+					"wxUSE_BASE=1",
+				);
 				INSTALL_PATH = "@executable_path/../Frameworks/";
 				OTHER_LDFLAGS = "$(OTHER_LDFLAGS)";
 			};
@@ -221,6 +231,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 40E3507E10EF2C130029DC34 /* wxcarbon.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 				PRODUCT_NAME = "$(PRODUCT_NAME)_static";
 			};
 			name = Debug;
@@ -229,6 +243,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 40E3507E10EF2C130029DC34 /* wxcarbon.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 				PRODUCT_NAME = "$(PRODUCT_NAME)_static";
 			};
 			name = Release;
diff --git a/build/osx/wxcocoa_in.xcodeproj/project.pbxproj b/build/osx/wxcocoa_in.xcodeproj/project.pbxproj
index 14c2973d59..48d1ecbdc0 100644
--- a/build/osx/wxcocoa_in.xcodeproj/project.pbxproj
+++ b/build/osx/wxcocoa_in.xcodeproj/project.pbxproj
@@ -188,7 +188,8 @@
 				EXECUTABLE_PREFIX = lib;
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"$(GCC_PREPROCESSOR_DEFINITIONS)",
-					WXUSINGDLL,
+					WXMAKINGDLL,
+					"wxUSE_BASE=1",
 				);
 				INSTALL_PATH = "@executable_path/../Frameworks/";
 				OTHER_LDFLAGS = "$(OTHER_LDFLAGS)";
@@ -202,7 +203,8 @@
 				EXECUTABLE_PREFIX = lib;
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"$(GCC_PREPROCESSOR_DEFINITIONS)",
-					WXUSINGDLL,
+					WXMAKINGDLL,
+					"wxUSE_BASE=1",
 				);
 				INSTALL_PATH = "@executable_path/../Frameworks/";
 				OTHER_LDFLAGS = "$(OTHER_LDFLAGS)";
@@ -229,6 +231,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 404BEEC910EC872F0080E2B8 /* wxcocoa.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 				PRODUCT_NAME = "$(PRODUCT_NAME)_static";
 			};
 			name = Debug;
@@ -237,6 +243,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 404BEEC910EC872F0080E2B8 /* wxcocoa.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 				PRODUCT_NAME = "$(PRODUCT_NAME)_static";
 			};
 			name = Release;
diff --git a/build/osx/wxiphone_in.xcodeproj/project.pbxproj b/build/osx/wxiphone_in.xcodeproj/project.pbxproj
index 8ab56438d7..2764d14777 100644
--- a/build/osx/wxiphone_in.xcodeproj/project.pbxproj
+++ b/build/osx/wxiphone_in.xcodeproj/project.pbxproj
@@ -145,6 +145,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 404BECEE10EBF6330080E2B8 /* wxiphone.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 			};
 			name = Debug;
 		};
@@ -152,6 +156,10 @@
 			isa = XCBuildConfiguration;
 			baseConfigurationReference = 404BECEE10EBF6330080E2B8 /* wxiphone.xcconfig */;
 			buildSettings = {
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"$(GCC_PREPROCESSOR_DEFINITIONS)",
+					"wxUSE_BASE=1",
+				);
 			};
 			name = Release;
 		};