diff --git a/Transmission.xcodeproj/project.pbxproj b/Transmission.xcodeproj/project.pbxproj
index 16e7dac61..a02bec7d7 100644
--- a/Transmission.xcodeproj/project.pbxproj
+++ b/Transmission.xcodeproj/project.pbxproj
@@ -2186,6 +2186,7 @@
 				GCC_MODEL_PPC64 = NO;
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
+				GCC_PREPROCESSOR_DEFINITIONS = "";
 				GCC_UNROLL_LOOPS = YES;
 				GCC_VERSION = 4.2;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = NO;
@@ -2328,6 +2329,7 @@
 				GCC_GENERATE_DEBUGGING_SYMBOLS = YES;
 				GCC_INCREASE_PRECOMPILED_HEADER_SHARING = YES;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
+				GCC_PREPROCESSOR_DEFINITIONS = NS_BLOCK_ASSERTIONS;
 				GCC_UNROLL_LOOPS = YES;
 				GCC_VERSION = 4.2;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = NO;
@@ -2365,6 +2367,7 @@
 				GCC_GENERATE_DEBUGGING_SYMBOLS = YES;
 				GCC_INCREASE_PRECOMPILED_HEADER_SHARING = YES;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
+				GCC_PREPROCESSOR_DEFINITIONS = "";
 				GCC_UNROLL_LOOPS = YES;
 				GCC_VERSION = 4.2;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = NO;