diff --git a/tests/length-tests.todo/Makefile b/tests/length-tests.todo/Makefile
index f79de70..7b8a374 100644
--- a/tests/length-tests.todo/Makefile
+++ b/tests/length-tests.todo/Makefile
@@ -1,6 +1,8 @@
 # See https://github.com/bxparks/EpoxyDuino for documentation about this
 # Makefile to compile and run Arduino programs natively on Linux or MacOS.
 
+EXTRA_CXXFLAGS=-g3 -O0
+
 APP_NAME := length-tests
 ARDUINO_LIBS := AUnit AceCommon AceTime TinyMqtt EspMock ESP8266WiFi  ESPAsyncTCP
 ARDUINO_LIB_DIRS := ../../../EspMock/libraries
diff --git a/tests/string-indexer-tests/Makefile b/tests/string-indexer-tests/Makefile
index c366385..dd82877 100644
--- a/tests/string-indexer-tests/Makefile
+++ b/tests/string-indexer-tests/Makefile
@@ -1,6 +1,8 @@
 # See https://github.com/bxparks/EpoxyDuino for documentation about this
 # Makefile to compile and run Arduino programs natively on Linux or MacOS.
 
+EXTRA_CXXFLAGS=-g3 -O0
+
 APP_NAME := string-indexer-tests
 ARDUINO_LIBS := AUnit AceCommon AceTime TinyMqtt EspMock ESP8266WiFi  ESPAsync
 ARDUINO_LIB_DIRS := ../../../EspMock/libraries