diff --git a/README.md b/README.md
index 744f9490..443383e9 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ wherever available:
 
 * OpenBSD with packages: install the `kyua` package with `pkg_add kyua`.
 
-* OS X (with Homebrew): install the `kyua` package with `brew install kyua`.
+* macOS (with Homebrew): install the `kyua` package with `brew install kyua`.
 
 Should you want to build and install Kyua from the source tree provided
 here, follow the instructions in the
diff --git a/integration/cmd_report_test.sh b/integration/cmd_report_test.sh
index 18a5db38..d3c39d0c 100644
--- a/integration/cmd_report_test.sh
+++ b/integration/cmd_report_test.sh
@@ -217,7 +217,7 @@ verbose_body() {
     # Switch to the current directory using its physical location and update
     # HOME accordingly.  Otherwise, the test below where we compare the value
     # of HOME in the output might fail if the path to HOME contains a symlink
-    # (as is the case in OS X when HOME points to the temporary directory.)
+    # (as is the case in macOS when HOME points to the temporary directory.)
     local real_cwd="$(pwd -P)"
     cd "${real_cwd}"
     HOME="${real_cwd}"
diff --git a/m4/developer-mode.m4 b/m4/developer-mode.m4
index ad946056..b011e3ad 100644
--- a/m4/developer-mode.m4
+++ b/m4/developer-mode.m4
@@ -67,7 +67,7 @@ AC_DEFUN([KYUA_DEVELOPER_MODE], [
     # Reasons given below.
     #
     # -Wold-style-cast: Raises errors when using TIOCGWINSZ, at least under
-    #                   Mac OS X.  This is due to the way _IOR is defined.
+    #                   macOS.  This is due to the way _IOR is defined.
     #
 
     try_c_cxx_flags="-D_FORTIFY_SOURCE=2 \