diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca5416bc1..ac02f8faa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 ### Fixed
 
+- `init` writes the bootstrap path and a custom tests directory to `.env` quoted, so a directory with a space runs afterwards instead of breaking every next run (#1411)
 - Failure source context stays inside a one-line test instead of listing the next function's assertions (#1420)
 - Parallel runs count tests under relative hidden paths and keep their results separate from matching visible paths (#1393)
 
diff --git a/docs/command-line.md b/docs/command-line.md
index b56841347..bd116df3c 100644
--- a/docs/command-line.md
+++ b/docs/command-line.md
@@ -1603,9 +1603,9 @@ Creates:
 - `tests/bootstrap.sh` - Setup file for test configuration
 - `tests/example_test.sh` - Sample test file to get started
 - `.github/workflows/tests.yml` - CI workflow using the official action
-- `.env` with `BASHUNIT_BOOTSTRAP=tests/bootstrap.sh`
+- `.env` with `BASHUNIT_BOOTSTRAP="tests/bootstrap.sh"`, plus `BASHUNIT_DEFAULT_PATH="<dir>"` for a custom directory so a bare `bashunit` runs it
 
-An existing `BASHUNIT_BOOTSTRAP=` line in `.env` is commented out first, so the new value
+An existing `BASHUNIT_BOOTSTRAP=` or `BASHUNIT_DEFAULT_PATH=` line in `.env` is commented out first, so the new value
 takes effect.
 
 ## upgrade
diff --git a/src/cli/init.sh b/src/cli/init.sh
index 858ade35b..ba1080831 100644
--- a/src/cli/init.sh
+++ b/src/cli/init.sh
@@ -1,5 +1,33 @@
 #!/usr/bin/env bash
 
+# Appends `line` to .env, leaves the file alone when it already holds it, and
+# comments an older, different `KEY=` out first. Commenting the line out and
+# appending an identical one made every re-init add a dead line, so a third
+# run left three (#1175); -Fx so a dot in the path is compared literally.
+function bashunit::init::write_env_line() {
+  local env_file=".env"
+  local line=$1
+  local key=${line%%=*}
+  if [ ! -f "$env_file" ]; then
+    printf '%s\n' "$line" >"$env_file"
+    echo "> Created $env_file"
+    return
+  fi
+  if grep -Fxq "$line" "$env_file"; then
+    echo "> $env_file already sets $key"
+    return
+  fi
+  if grep -q "^$key=" "$env_file"; then
+    if bashunit::check_os::is_macos; then
+      sed -i '' -e "s/^$key=/#&/" "$env_file"
+    else
+      sed -i -e "s/^$key=/#&/" "$env_file"
+    fi
+  fi
+  printf '%s\n' "$line" >>"$env_file"
+  echo "> Updated $env_file"
+}
+
 function bashunit::init::project() {
   local tests_dir="${1:-$BASHUNIT_DEFAULT_PATH}"
   mkdir -p "$tests_dir"
@@ -47,29 +75,19 @@ SH
     echo "> Created $workflow_file"
   fi
 
-  local env_file=".env"
-  local env_line="BASHUNIT_BOOTSTRAP=$bootstrap_file"
-  if [ -f "$env_file" ]; then
-    # Already pointing where this run would point it: leave the file alone.
-    # Commenting the line out and appending an identical one made every re-init
-    # add a dead line, so a third run left three (#1175). -Fx so a dot in the
-    # path is compared literally.
-    if grep -Fxq "$env_line" "$env_file"; then
-      echo "> $env_file already sets BASHUNIT_BOOTSTRAP"
-    else
-      if grep -q "^BASHUNIT_BOOTSTRAP=" "$env_file"; then
-        if bashunit::check_os::is_macos; then
-          sed -i '' -e "s/^BASHUNIT_BOOTSTRAP=/#&/" "$env_file"
-        else
-          sed -i -e "s/^BASHUNIT_BOOTSTRAP=/#&/" "$env_file"
-        fi
-      fi
-      echo "$env_line" >>"$env_file"
-      echo "> Updated $env_file"
-    fi
-  else
-    echo "$env_line" >"$env_file"
-    echo "> Created $env_file"
+  # .env is sourced as shell, so values are written double-quoted and the
+  # characters that are special inside double quotes are escaped: a directory
+  # with a space stays one assignment instead of turning into a command.
+  local quoted="$tests_dir"
+  quoted=${quoted//\\/\\\\}
+  quoted=${quoted//\"/\\\"}
+  quoted=${quoted//\$/\\\$}
+  quoted=${quoted//\`/\\\`}
+  bashunit::init::write_env_line "BASHUNIT_BOOTSTRAP=\"$quoted/bootstrap.sh\""
+  # A custom directory is otherwise invisible to the next bare `bashunit`,
+  # which searches BASHUNIT_DEFAULT_PATH ("tests").
+  if [ "$tests_dir" != "$BASHUNIT_DEFAULT_PATH" ]; then
+    bashunit::init::write_env_line "BASHUNIT_DEFAULT_PATH=\"$quoted\""
   fi
 
   echo "> bashunit initialized in $tests_dir"
diff --git a/tests/acceptance/bashunit_init_test.sh b/tests/acceptance/bashunit_init_test.sh
index fcea215e2..6a776e875 100644
--- a/tests/acceptance/bashunit_init_test.sh
+++ b/tests/acceptance/bashunit_init_test.sh
@@ -64,10 +64,26 @@ function test_bashunit_init_updates_env() {
   assert_file_exists "custom/example_test.sh"
   assert_file_exists "custom/bootstrap.sh"
   assert_file_contains .env "#BASHUNIT_BOOTSTRAP=old/bootstrap.sh"
-  assert_file_contains .env "BASHUNIT_BOOTSTRAP=custom/bootstrap.sh"
+  assert_file_contains .env 'BASHUNIT_BOOTSTRAP="custom/bootstrap.sh"'
   popd >/dev/null
 }
 
+# A directory with a space is a valid project directory. `.env` is sourced as
+# shell, so an unquoted BASHUNIT_BOOTSTRAP turns the second word into a command
+# and the next run dies with "No such file or directory" naming a path the user
+# never typed.
+function test_bashunit_init_with_a_space_in_the_directory_runs_afterwards() {
+  pushd "$TMP_DIR" >/dev/null
+  "$BASHUNIT_PATH" init "my tests" >/dev/null
+
+  local output
+  output="$($BASHUNIT_PATH --no-color 2>&1)"
+  popd >/dev/null
+
+  assert_not_contains "No such file or directory" "$output"
+  assert_contains "1 passed" "$output"
+}
+
 # `bashunit init` is run more than once in practice -- re-scaffolding, or a
 # setup script that is not guarded. The files it writes are idempotent; .env
 # was not: every run commented out the previous BASHUNIT_BOOTSTRAP and appended