Index: ObjFW.xcodeproj/project.pbxproj
==================================================================
--- ObjFW.xcodeproj/project.pbxproj
+++ ObjFW.xcodeproj/project.pbxproj
@@ -2116,10 +2116,11 @@
 		1DEB919408733D9F0010E9CD /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				GCC_C_LANGUAGE_STANDARD = c11;
 				GCC_OPTIMIZATION_LEVEL = 2;
+				GCC_WARN_PEDANTIC = YES;
 				OTHER_CFLAGS = (
 					"-fexceptions",
 					"-fconstant-string-class=OFConstantString",
 					"-fno-constant-cfstrings",
 					"-fno-common",
@@ -2143,10 +2144,11 @@
 		1DEB919508733D9F0010E9CD /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				GCC_C_LANGUAGE_STANDARD = c11;
 				GCC_OPTIMIZATION_LEVEL = 2;
+				GCC_WARN_PEDANTIC = YES;
 				OTHER_CFLAGS = (
 					"-fexceptions",
 					"-fconstant-string-class=OFConstantString",
 					"-fno-constant-cfstrings",
 					"-fno-common",

Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -92,10 +92,11 @@
 		AX_CHECK_COMPILER_FLAGS(-std=c99,
 			[OBJCFLAGS="$OBJCFLAGS -std=c99"])
 	])
 ])
 
+AX_CHECK_COMPILER_FLAGS(-pedantic, [OBJCFLAGS="$OBJCFLAGS -pedantic"])
 AX_CHECK_COMPILER_FLAGS(-pipe, [OBJCFLAGS="$OBJCFLAGS -pipe"])
 AX_CHECK_COMPILER_FLAGS(-fno-common, [OBJCFLAGS="$OBJCFLAGS -fno-common"])
 AX_CHECK_COMPILER_FLAGS(-fno-constant-cfstrings, [
 	OBJCFLAGS="$OBJCFLAGS -fno-constant-cfstrings"
 	AC_SUBST(NO_CONST_CFSTRINGS, "-fno-constant-cfstrings")