diff --git a/Transmission.xcodeproj/project.pbxproj b/Transmission.xcodeproj/project.pbxproj
index 30719237a..ec88d0823 100644
--- a/Transmission.xcodeproj/project.pbxproj
+++ b/Transmission.xcodeproj/project.pbxproj
@@ -2333,7 +2333,10 @@
 				GCC_GENERATE_DEBUGGING_SYMBOLS = YES;
 				GCC_INCREASE_PRECOMPILED_HEADER_SHARING = YES;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
-				GCC_PREPROCESSOR_DEFINITIONS = NS_BLOCK_ASSERTIONS;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					NDEBUG,
+					NS_BLOCK_ASSERTIONS,
+				);
 				GCC_UNROLL_LOOPS = YES;
 				GCC_VERSION = 4.2;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = NO;