diff --git a/src/template/darwin b/src/template/darwin
index 32414d21a9..1868c147cb 100644
--- a/src/template/darwin
+++ b/src/template/darwin
@@ -3,11 +3,27 @@
 # Note: Darwin is the original code name for macOS, also known as OS X.
 # We still use "darwin" as the port name, partly because config.guess does.
 
-# Select where system include files should be sought.
+# Select where system include files should be sought, if user didn't say.
 if test x"$PG_SYSROOT" = x"" ; then
-  PG_SYSROOT=`xcodebuild -version -sdk macosx Path 2>/dev/null`
+  # This is far more complicated than it ought to be.  We first ask
+  # "xcrun --show-sdk-path", which seems to match the default -isysroot
+  # setting of Apple's compilers.  However, that may produce no result or
+  # a result that is not version-specific (i.e., just ".../SDKs/MacOSX.sdk").
+  # Using a version-specific sysroot seems desirable, so if there are not
+  # digits in the directory name, try "xcrun --sdk macosx --show-sdk-path";
+  # and if that still doesn't work, fall back to asking xcodebuild,
+  # which is often a good deal slower.
+  PG_SYSROOT=`xcrun --show-sdk-path 2>/dev/null`
+  if expr x"$PG_SYSROOT" : '.*[0-9]\.[0-9][^/]*$' >/dev/null ; then : okay
+  else
+    PG_SYSROOT=`xcrun --sdk macosx --show-sdk-path 2>/dev/null`
+    if expr x"$PG_SYSROOT" : '.*[0-9]\.[0-9][^/]*$' >/dev/null ; then : okay
+    else
+      PG_SYSROOT=`xcodebuild -version -sdk macosx Path 2>/dev/null`
+    fi
+  fi
 fi
-# Old xcodebuild versions may produce garbage, so validate the result.
+# Validate the result: if it doesn't point at a directory, ignore it.
 if test x"$PG_SYSROOT" != x"" ; then
   if test -d "$PG_SYSROOT" ; then
     CPPFLAGS="-isysroot $PG_SYSROOT $CPPFLAGS"