@@ -117,20 +117,20 @@
 		#import <objc/objc.h>
 		#ifdef __GNU_LIBOBJC__
 		yes
 		#endif
 	], [
-		test x"$objc_runtime" = "x" && objc_runtime="GNU"
+		test x"$objc_runtime" = x"" && objc_runtime="GNU"
 	], [
 		dnl TODO: This is ugly. Let's think of a better check.
 		AC_EGREP_CPP(yes, [
 			#import <objc/objc.h>
 			#ifdef __objc_INCLUDE_GNU
 			yes
 			#endif
 		], [
-			test x"$objc_runtime" = "x" && objc_runtime="old GNU"
+			test x"$objc_runtime" = x"" && objc_runtime="old GNU"
 		], [
 			objc_runtime="Apple"
 		])
 	])
 ])
@@ -175,14 +175,14 @@
 AC_CHECK_FUNC(objc_enumerationMutation, [
 	AC_DEFINE(HAVE_OBJC_ENUMERATIONMUTATION, 1,
 		[Whether we have objc_enumerationMutation])
 ])
 
-AC_PATH_TOOL(AR, ar)
+AC_CHECK_TOOL(AR, ar)
 AC_PROG_RANLIB
 AC_ARG_ENABLE(shared,
-	AS_HELP_STRING([--disable-shared], [don't build shared library]))
+	AS_HELP_STRING([--disable-shared], [do not build shared library]))
 AS_IF([test x"$enable_shared" != x"no"], [
 	BUILDSYS_SHARED_LIB
 	AC_SUBST(OBJFW_SHARED_LIB, "${LIB_PREFIX}objfw${LIB_SUFFIX}")
 	AC_SUBST(EXCEPTIONS_LIB_A, "exceptions.lib.a")
 	AC_SUBST(EXCEPTIONS_EXCEPTIONS_LIB_A, "exceptions/exceptions.lib.a")
@@ -193,11 +193,11 @@
 	AC_SUBST(EXCEPTIONS_A, "exceptions.a")
 	AC_SUBST(EXCEPTIONS_EXCEPTIONS_A, "exceptions/exceptions.a")
 ])
 
 AC_DEFINE_UNQUOTED(PLUGIN_SUFFIX, "$PLUGIN_SUFFIX", [Suffix for plugins])
-AS_IF([test x"$PLUGIN_SUFFIX" != "x"], [
+AS_IF([test x"$PLUGIN_SUFFIX" != x""], [
 	AC_SUBST(OFPLUGIN_M, "OFPlugin.m")
 	AC_SUBST(OFPLUGINTESTS_M, "OFPluginTests.m")
 	AC_SUBST(TESTPLUGIN, "plugin")
 	AC_DEFINE(OF_PLUGINS, 1, [Whether we have plugin support])
 	AC_SUBST(OFPLUGINS_DEF, "-DOF_PLUGINS")
@@ -533,13 +533,13 @@
 AS_IF([test x"$cross_compiling" = x"yes"], [
 	AC_SUBST(BIN_PREFIX, "$host-")
 
 	case "$host" in
 		*-*-mingw*)
-			AC_PATH_PROG(WINE, wine)
+			AC_CHECK_PROG(WINE, wine)
 
-			AS_IF([test x"$WINE" != "x"], [
+			AS_IF([test x"$WINE" != x""], [
 				AC_SUBST(TESTS, "tests")
 				AC_SUBST(TEST_LAUNCHER, "$WINE")
 			])
 			;;
 	esac
@@ -549,13 +549,13 @@
 
 BUILDSYS_INIT
 BUILDSYS_TOUCH_DEPS
 
 dnl We don't call AC_PROG_CPP, but only AC_PROG_OBJCPP and set CPP to OBJCPP
-dnl and add OBJCPPFLAGS to CPPFLAGS, thus we need to AC_SUBST these ourself
+dnl and add OBJCPPFLAGS to CPPFLAGS, thus we need to AC_SUBST these ourself.
 AC_SUBST(CPP)
 AC_SUBST(CPPFLAGS)
 
 AC_SUBST(PACKAGE, ObjFW)
 AC_CONFIG_FILES([buildsys.mk extra.mk utils/objfw-config])
 AC_CONFIG_HEADERS([config.h src/objfw-defs.h])
 AC_OUTPUT