diff --git a/teensy/Makefile b/teensy/Makefile
index 8c864161ab..575e15e542 100644
--- a/teensy/Makefile
+++ b/teensy/Makefile
@@ -207,7 +207,7 @@ GEN_PINS_AF_CONST = $(HEADER_BUILD)/pins_af_const.h
 GEN_PINS_AF_PY = $(BUILD)/pins_af.py
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(STM_SRC_C)
+SRC_QSTR += $(SRC_C) $(STM_SRC_C) $(LIB_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=