diff --git a/src/auto/configure b/src/auto/configure
index 0dd54ced65..6bea619094 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -14903,12 +14903,12 @@ $as_echo "using default" >&6; }
 fi
 
 
-    vim_major_version_string=`grep -m 1 'define.*VIM_VERSION_MAJOR' $srcdir/version.h|sed -E -e 's/^.*([0-9]+).*/\1/'`
-  vim_minor_version_string=`grep -m 1 'define.*VIM_VERSION_MINOR' $srcdir/version.h|sed -E -e 's/^.*([0-9]+).*/\1/'`
-  snapshot=`grep -C2 "Add new patch number below this line" $srcdir/version.c|tail -1|sed -E -e 's/^ *([0-9]+),.*/\1/'`
+    vim_major_version_string=`/usr/bin/grep -m 1 'define.*VIM_VERSION_MAJOR' $srcdir/version.h|sed -E -e 's/^.*([0-9]+).*/\1/'`
+  vim_minor_version_string=`/usr/bin/grep -m 1 'define.*VIM_VERSION_MINOR' $srcdir/version.h|sed -E -e 's/^.*([0-9]+).*/\1/'`
+  snapshot=`/usr/bin/grep -C2 "Add new patch number below this line" $srcdir/version.c|tail -1|sed -E -e 's/^ *([0-9]+),.*/\1/'`
   vim_short_version_string="$vim_major_version_string.$vim_minor_version_string.$snapshot"
 
-  if echo "$vim_short_version_string" | grep -q "^\d\+\.\d\+\.\d\+$"; then
+  if echo "$vim_short_version_string" | /usr/bin/grep -q "^[[:digit:]]\+\.[[:digit:]]\+\.[[:digit:]]\+$"; then
     XCODEFLAGS="$XCODEFLAGS VIM_SHORT_VERSION_STRING=$vim_short_version_string"
   else
     as_fn_error $? "could not parse Vim version: $vim_short_version_string" "$LINENO" 5
diff --git a/src/configure.ac b/src/configure.ac
index 9c527c8092..10b081408e 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -4543,12 +4543,12 @@ if test "x$MACOS_X" = "xyes"; then
     [ AC_MSG_RESULT(using default) ])
 
   dnl Set CFBundleShortVersionString of Info.plist
-  vim_major_version_string=`grep -m 1 'define.*VIM_VERSION_MAJOR' $srcdir/version.h|sed -E -e 's/^.*([[0-9]]+).*/\1/'`
-  vim_minor_version_string=`grep -m 1 'define.*VIM_VERSION_MINOR' $srcdir/version.h|sed -E -e 's/^.*([[0-9]]+).*/\1/'`
-  snapshot=`grep -C2 "Add new patch number below this line" $srcdir/version.c|tail -1|sed -E -e 's/^ *([[0-9]]+),.*/\1/'`
+  vim_major_version_string=`/usr/bin/grep -m 1 'define.*VIM_VERSION_MAJOR' $srcdir/version.h|sed -E -e 's/^.*([[0-9]]+).*/\1/'`
+  vim_minor_version_string=`/usr/bin/grep -m 1 'define.*VIM_VERSION_MINOR' $srcdir/version.h|sed -E -e 's/^.*([[0-9]]+).*/\1/'`
+  snapshot=`/usr/bin/grep -C2 "Add new patch number below this line" $srcdir/version.c|tail -1|sed -E -e 's/^ *([[0-9]]+),.*/\1/'`
   vim_short_version_string="$vim_major_version_string.$vim_minor_version_string.$snapshot"
 
-  if echo "$vim_short_version_string" | grep -q "^\d\+\.\d\+\.\d\+$"; then
+  if echo "$vim_short_version_string" | /usr/bin/grep -q "^[[[:digit:]]]\+\.[[[:digit:]]]\+\.[[[:digit:]]]\+$"; then
     XCODEFLAGS="$XCODEFLAGS VIM_SHORT_VERSION_STRING=$vim_short_version_string"
   else
     AC_MSG_ERROR(could not parse Vim version: $vim_short_version_string)