diff --git a/src/tools/pginclude/pgcompinclude b/src/tools/pginclude/pgcompinclude
index afc079a31032ce65beb86c3ab46dcdc50a8aa9dc..5625f34343f0ef74f3eececc46e640e70137b278 100755
--- a/src/tools/pginclude/pgcompinclude
+++ b/src/tools/pginclude/pgcompinclude
@@ -3,6 +3,9 @@
 # takes -v option to display compile failure message and line numbers
 # src/tools/pginclude/pgcompinclude
 
+: ${CC:=cc}
+: ${PGSRC:=src}
+
 if ! pgdefine
 then	echo "pgdefine must be in your PATH" 1>&2
 	exit 1
@@ -29,9 +32,9 @@ do
 
 	# Use -O1 to get warnings only generated by optimization,
 	# but -O2 is too slow.
-	cc -fsyntax-only -Werror -Wall -Wmissing-prototypes \
-		-Wmissing-declarations -I/pg/include -I/pg/backend \
-		-I/pg/interfaces/libpq -I`dirname $FILE` $CFLAGS -O1 -c /tmp/$$.c \
+	$CC -fsyntax-only -Werror -Wall -Wmissing-prototypes \
+		-Wmissing-declarations -I$PGSRC/include -I$PGSRC/backend \
+		-I$PGSRC/interfaces/libpq -I`dirname $FILE` $CFLAGS -O1 -c /tmp/$$.c \
 		-o /tmp/$$.o >/tmp/$$ 2>&1
 	if [ "$?" -ne 0 ]
 	then	echo "$FILE"
diff --git a/src/tools/pginclude/pgrminclude b/src/tools/pginclude/pgrminclude
index 93a535c906745b849a23b761079266497fb8809b..75a7c6d5c706b049588b9cdee187752d95b779a7 100755
--- a/src/tools/pginclude/pgrminclude
+++ b/src/tools/pginclude/pgrminclude
@@ -18,6 +18,9 @@
 # be compiled on the platform from which pgrminclude is run cannot be
 # processed, and are skipped.
 
+: ${CC:=cc}
+: ${PGSRC:=src}
+
 if ! pgdefine
 then	echo "pgdefine must be in your PATH" 1>&2
 	exit 1
@@ -104,9 +107,9 @@ compile_file() {
 
 	# Use -O1 to get warnings only generated by optimization,
 	# but -O2 is too slow.
-	cc -fsyntax-only -Werror -Wall -Wmissing-prototypes \
-		-Wmissing-declarations -I/pg/include -I/pg/backend \
-		-I/pg/interfaces/libpq -I`dirname $FILE` $CFLAGS -O1 -c /tmp/$$.c \
+	$CC -fsyntax-only -Werror -Wall -Wmissing-prototypes \
+		-Wmissing-declarations -I$PGSRC/include -I$PGSRC/backend \
+		-I$PGSRC/interfaces/libpq -I`dirname $FILE` $CFLAGS -O1 -c /tmp/$$.c \
 		-o /tmp/$$.o >/tmp/$$ 2>&1
 	if [ "$?" -eq 0 ]
 	then	[ "$INCLUDE" -o "$VERBOSE" ] && echo "$FILE $INCLUDE"