diff --git a/Makefile b/Makefile
index 809f067a..e1a0c5c1 100644
--- a/Makefile
+++ b/Makefile
@@ -125,6 +125,7 @@ $(PGDIR):
 	cd $(PGDIR); patch -p1 < $(root_dir)/patches/07_plpgsql_start_finish_datums.patch
 	cd $(PGDIR); patch -p1 < $(root_dir)/patches/08_avoid_zero_length_delimiter_in_regression_tests.patch
 	cd $(PGDIR); patch -p1 < $(root_dir)/patches/09_allow_param_junk.patch
+	cd $(PGDIR); patch -p1 < $(root_dir)/patches/10_ifndef_namedatalen.patch
 	cd $(PGDIR); ./configure $(PG_CONFIGURE_FLAGS)
 	cd $(PGDIR); rm src/pl/plpgsql/src/pl_gram.h
 	cd $(PGDIR); make -C src/pl/plpgsql/src pl_gram.h
diff --git a/patches/10_ifndef_namedatalen.patch b/patches/10_ifndef_namedatalen.patch
new file mode 100644
index 00000000..7aade806
--- /dev/null
+++ b/patches/10_ifndef_namedatalen.patch
@@ -0,0 +1,14 @@
+diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
+index a1a93ad..c978d76 100644
+--- a/src/include/pg_config_manual.h
++++ b/src/include/pg_config_manual.h
+@@ -26,7 +26,9 @@
+  *
+  * Changing this requires an initdb.
+  */
++#ifndef NAMEDATALEN
+ #define NAMEDATALEN 64
++#endif
+
+ /*
+  * Maximum number of arguments to a function.
diff --git a/src/postgres/include/pg_config_manual.h b/src/postgres/include/pg_config_manual.h
index a1a93ad7..c978d76d 100644
--- a/src/postgres/include/pg_config_manual.h
+++ b/src/postgres/include/pg_config_manual.h
@@ -26,7 +26,9 @@
  *
  * Changing this requires an initdb.
  */
+#ifndef NAMEDATALEN
 #define NAMEDATALEN 64
+#endif
 
 /*
  * Maximum number of arguments to a function.