diff --git a/doc/common.m4 b/doc/common.m4
index 13c7f6c09..871a7cbf8 100644
--- a/doc/common.m4
+++ b/doc/common.m4
@@ -1,7 +1,8 @@
 m4_dnl m4 macro definitions used in all hledger package docs.
 m4_dnl m4 commands in Shake.hs always load this file first.
+m4_dnl PACKAGE/defs.m4 can add to/override these definitions.
 m4_dnl
-m4_dnl "m4_dnl" causes the rest of the line to be ignored.
+m4_dnl "m4_dnl" ignores the rest of the line (including newline).
 m4_dnl
 m4_dnl {{ }} will be our quoting delimiters
 m4_changequote({{,}})m4_dnl
@@ -9,17 +10,9 @@ m4_dnl
 m4_dnl _MACRO_ will be the naming convention for our macros
 m4_define({{_include_}},     m4_defn({{m4_include}})              )m4_dnl
 m4_dnl
-m4_dnl These can be defined here or (with higher precedence) in PACKAGE/defs.m4:
-m4_dnl
 m4_dnl Author to show in man pages.
 m4_define({{_author_}}, {{}})m4_dnl
 m4_dnl
-m4_dnl Date to show in man pages. Updated by make setdate.
-m4_define({{_monthyear_}}, {{February 2019}})m4_dnl
-m4_dnl
-m4_dnl Program version. Updated by make setversion.
-m4_define({{_version_}}, {{1.13}})m4_dnl
-m4_dnl
 m4_dnl Macros for conditionally including format-specific content
 m4_dnl $1 is the manual's web slug: hledger, hledger-ui, journal, csv etc.
 m4_define({{_man_}},         m4_ifdef({{MAN}},{{$1}})             )m4_dnl
diff --git a/hledger-api/defs.m4 b/hledger-api/defs.m4
index 028d4ef99..b4f48ed53 100644
--- a/hledger-api/defs.m4
+++ b/hledger-api/defs.m4
@@ -1,3 +1,7 @@
 m4_dnl m4 macro definitions used in this package's docs.
 m4_dnl
+m4_dnl Program version. Updated by make setversion.
 m4_define({{_version_}}, {{1.13}})m4_dnl
+m4_dnl
+m4_dnl Date to show in man pages. Updated by make setdate.
+m4_define({{_monthyear_}}, {{February 2019}})m4_dnl
diff --git a/hledger-lib/defs.m4 b/hledger-lib/defs.m4
index 49e107324..555b94c72 100644
--- a/hledger-lib/defs.m4
+++ b/hledger-lib/defs.m4
@@ -1,3 +1,7 @@
 m4_dnl m4 macro definitions used in this package's docs.
 m4_dnl
+m4_dnl Program version. Updated by make setversion.
 m4_define({{_version_}}, {{1.13.1}})m4_dnl
+m4_dnl
+m4_dnl Date to show in man pages. Updated by make setdate.
+m4_define({{_monthyear_}}, {{February 2019}})m4_dnl
diff --git a/hledger-ui/defs.m4 b/hledger-ui/defs.m4
index 028d4ef99..b4f48ed53 100644
--- a/hledger-ui/defs.m4
+++ b/hledger-ui/defs.m4
@@ -1,3 +1,7 @@
 m4_dnl m4 macro definitions used in this package's docs.
 m4_dnl
+m4_dnl Program version. Updated by make setversion.
 m4_define({{_version_}}, {{1.13}})m4_dnl
+m4_dnl
+m4_dnl Date to show in man pages. Updated by make setdate.
+m4_define({{_monthyear_}}, {{February 2019}})m4_dnl
diff --git a/hledger-web/defs.m4 b/hledger-web/defs.m4
index 028d4ef99..b4f48ed53 100644
--- a/hledger-web/defs.m4
+++ b/hledger-web/defs.m4
@@ -1,3 +1,7 @@
 m4_dnl m4 macro definitions used in this package's docs.
 m4_dnl
+m4_dnl Program version. Updated by make setversion.
 m4_define({{_version_}}, {{1.13}})m4_dnl
+m4_dnl
+m4_dnl Date to show in man pages. Updated by make setdate.
+m4_define({{_monthyear_}}, {{February 2019}})m4_dnl
diff --git a/hledger/defs.m4 b/hledger/defs.m4
index 651e5c979..4c8fe0c8a 100644
--- a/hledger/defs.m4
+++ b/hledger/defs.m4
@@ -1,3 +1,7 @@
 m4_dnl m4 macro definitions used in this package's docs.
 m4_dnl
+m4_dnl Program version. Updated by make setversion.
 m4_define({{_version_}}, {{1.13.2}})m4_dnl
+m4_dnl
+m4_dnl Date to show in man pages. Updated by make setdate.
+m4_define({{_monthyear_}}, {{February 2019}})m4_dnl