diff --git a/test/test_bootstrap.py b/test/test_bootstrap.py
index 4865ece5..c1882e5d 100644
--- a/test/test_bootstrap.py
+++ b/test/test_bootstrap.py
@@ -22,6 +22,7 @@ def test_bootstrap(
         paths.bootstrap.write(
             '#!/bin/bash\n'
             f'echo {expect}\n'
+            f'[[ $(id -un) = $YADM_USER ]] && echo "user is set"\n'
             f'exit {code}\n'
         )
         paths.bootstrap.chmod(0o775)
@@ -30,6 +31,7 @@ def test_bootstrap(
     if exists and executable:
         assert run.err == ''
         assert expect in run.out
+        assert 'user is set' in run.out
     else:
         assert expect in run.err
         assert run.out == ''
diff --git a/test/test_unit_set_alt_values.py b/test/test_unit_set_alt_values.py
index 8eb9c100..3730f34a 100644
--- a/test/test_unit_set_alt_values.py
+++ b/test/test_unit_set_alt_values.py
@@ -27,7 +27,7 @@ def test_set_alt_values(
         YADM_TEST=1 source {yadm} &&
         set_operating_system &&
         YADM_DIR={paths.yadm} YADM_DATA={paths.data} configure_paths &&
-        set_alt_values
+        ALT_VALUES_SET=0 set_alt_values
         echo "class='$YADM_CLASS'"
         echo "os='$YADM_OS'"
         echo "host='$YADM_HOSTNAME'"
@@ -69,7 +69,7 @@ def test_distro(runner, yadm):
         YADM_TEST=1 source {yadm}
         function config() {{ echo "$1"; }}
         function query_distro() {{ echo "testdistro"; }}
-        set_alt_values
+        ALT_VALUES_SET=0 set_alt_values
         echo "distro='$YADM_DISTRO'"
     """
     run = runner(command=['bash'], inp=script)
diff --git a/yadm b/yadm
index f74c5021..78ce653a 100755
--- a/yadm
+++ b/yadm
@@ -63,6 +63,7 @@ ENCRYPT_INCLUDE_FILES="unparsed"
 
 LEGACY_WARNING_ISSUED=0
 INVALID_ALT=()
+ALT_VALUES_SET="${YADM_TEST:-0}"
 
 GPG_OPTS=()
 OPENSSL_OPTS=()
@@ -596,6 +597,9 @@ function remove_stale_links() {
 
 function set_alt_values() {
 
+  [[ $ALT_VALUES_SET = 1 ]] && return
+  ALT_VALUES_SET=1
+
   export YADM_CLASS
   export YADM_ARCH
   export YADM_OS
@@ -698,6 +702,8 @@ function bootstrap() {
   # GIT_DIR should not be set for user's bootstrap code
   unset GIT_DIR
 
+  set_alt_values
+
   echo "Executing $YADM_BOOTSTRAP"
   exec "$YADM_BOOTSTRAP"
 
@@ -1770,6 +1776,8 @@ function invoke_hook() {
     export -f unix_path
     export -f mixed_path
 
+    set_alt_values
+
     "$hook_command"
     hook_status=$?
 
diff --git a/yadm.1 b/yadm.1
index 6f4ba6ba..b2610a19 100644
--- a/yadm.1
+++ b/yadm.1
@@ -112,7 +112,9 @@ to "false".
 .B bootstrap
 Execute
 .I $HOME/.config/yadm/bootstrap
-if it exists.
+if it exists. The variables that are set when processing Jinja or ESH templates
+(see the TEMPLATES section) are set in the environment (except for
+.IR YADM_SOURCE ).
 .TP
 .BI clone " url
 Clone a remote repository for tracking dotfiles.
@@ -876,7 +878,10 @@ will never be run. This allows one to "short-circuit" any operation using a
 .I pre_
 hook.
 
-Hooks have the following environment variables available to them at runtime:
+Hooks have the following variables, plus the variables set when processing
+Jinja or ESH templates (see the TEMPLATES section), available to them as
+environment variables at runtime (except for
+.IR YADM_SOURCE ).
 .TP
 .B YADM_HOOK_COMMAND
 The command which triggered the hook