diff --git a/examples/c/run_tests.sh b/examples/c/run_tests.sh
index c4eb19bb6ad..1cfb586d292 100755
--- a/examples/c/run_tests.sh
+++ b/examples/c/run_tests.sh
@@ -1,3 +1,4 @@
+#!/bin/sh
 # This is a test script for PIO examples.
 # Ed Hartnett 5/7/18
 
@@ -5,7 +6,7 @@
 set -e
 
 # Stop loop if ctrl-c is pressed.
-trap exit SIGINT SIGTERM
+trap exit INT TERM
 
 printf 'running PIO examples...\n'
 
diff --git a/tests/cunit/run_tests.sh b/tests/cunit/run_tests.sh
index 5261b41aee5..105bfd1b90c 100755
--- a/tests/cunit/run_tests.sh
+++ b/tests/cunit/run_tests.sh
@@ -1,3 +1,4 @@
+#!/bin/sh
 # This is a test script for PIO.
 # Ed Hartnett
 
@@ -5,7 +6,7 @@
 set -e
 
 # Stop loop if ctrl-c is pressed.
-trap exit SIGINT SIGTERM
+trap exit INT TERM
 
 printf 'running PIO tests...\n'