diff --git a/bash-preexec.sh b/bash-preexec.sh
index 641346a..cd7bee5 100644
--- a/bash-preexec.sh
+++ b/bash-preexec.sh
@@ -47,6 +47,12 @@ if [[ -z "${BASH_VERSINFO-}" ]] || (( BASH_VERSINFO[0] < 3 || (BASH_VERSINFO[0]
     return 1
 fi
 
+# We do not enable bash-preexc in non-interactive shells (except in tests).
+# `__bp_inside_test` is set in test/*.bats in bash-preexec repository.
+if [[ $- != *i* && ! ${__bp_inside_test-} ]]; then
+   return 0
+fi
+
 # Avoid duplicate inclusion
 if [[ -n "${bash_preexec_imported:-}" || -n "${__bp_imported:-}" ]]; then
     return 0
diff --git a/test/bash-preexec.bats b/test/bash-preexec.bats
index 152d5a6..c1593ea 100644
--- a/test/bash-preexec.bats
+++ b/test/bash-preexec.bats
@@ -1,5 +1,11 @@
 #!/usr/bin/env bats
 
+# This variable tells bash-preexec.sh that it is loaded for testing purposes.
+# bash-preexec.sh is intended to be used in interactive shell sessions, so it
+# is disabled in non-interactive shells by default.  However, it still needs to
+# be loaded in non-interactive shells for the Bats tests,
+__bp_inside_test=yes
+
 setup() {
   PROMPT_COMMAND=''        # in case the invoking shell has set this
   history -s fake command  # preexec requires there be some history
diff --git a/test/include-test.bats b/test/include-test.bats
index 36a5f25..7d2bc38 100644
--- a/test/include-test.bats
+++ b/test/include-test.bats
@@ -1,5 +1,11 @@
 #!/usr/bin/env bats
 
+# This variable tells bash-preexec.sh that it is loaded for testing purposes.
+# bash-preexec.sh is intended to be used in interactive shell sessions, so it
+# is disabled in non-interactive shells by default.  However, it still needs to
+# be loaded in non-interactive shells for the Bats tests,
+__bp_inside_test=yes
+
 @test "should not import if it's already defined" {
   bash_preexec_imported="defined"
   source "${BATS_TEST_DIRNAME}/../bash-preexec.sh"