diff --git a/SDWebImage.xcodeproj/project.pbxproj b/SDWebImage.xcodeproj/project.pbxproj
index 292f0543..8b0c6fd4 100644
--- a/SDWebImage.xcodeproj/project.pbxproj
+++ b/SDWebImage.xcodeproj/project.pbxproj
@@ -2955,6 +2955,7 @@
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"DEBUG=1",
+					"SD_WEBP=1",
 					"$(inherited)",
 				);
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
@@ -3007,7 +3008,10 @@
 				);
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_NO_COMMON_BLOCKS = YES;
-				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"SD_WEBP=1",
+					"$(inherited)",
+				);
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_MISSING_FIELD_INITIALIZERS = YES;