diff --git a/Makefile.pre.in b/Makefile.pre.in
index 9c68b1fd6cf9d9..5535f47d65ba5d 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -186,12 +186,16 @@ PYTHONFRAMEWORKPREFIX=	@PYTHONFRAMEWORKPREFIX@
 PYTHONFRAMEWORKINSTALLDIR= @PYTHONFRAMEWORKINSTALLDIR@
 PYTHONFRAMEWORKINSTALLNAMEPREFIX= @PYTHONFRAMEWORKINSTALLNAMEPREFIX@
 RESSRCDIR= @RESSRCDIR@
-# Deployment target selected during configure, to be checked
+# macOS deployment target selected during configure, to be checked
 # by distutils. The export statement is needed to ensure that the
 # deployment target is active during build.
 MACOSX_DEPLOYMENT_TARGET=@CONFIGURE_MACOSX_DEPLOYMENT_TARGET@
 @EXPORT_MACOSX_DEPLOYMENT_TARGET@export MACOSX_DEPLOYMENT_TARGET
-# iOS Deployment target selected during configure
+
+# iOS Deployment target selected during configure. Unlike macOS, the iOS
+# deployment target is controlled using `-mios-version-min` arguments added to
+# CFLAGS and LDFLAGS by the configure script. This variable is not used during
+# the build, and is only listed here so it will be included in sysconfigdata.
 IPHONEOS_DEPLOYMENT_TARGET=@IPHONEOS_DEPLOYMENT_TARGET@
 
 # Option to install to strip binaries