diff --git a/Cantera/ext/f2c_math/Makefile.am b/Cantera/ext/f2c_math/Makefile.am
index b07fca59e..7e8aabb7b 100644
--- a/Cantera/ext/f2c_math/Makefile.am
+++ b/Cantera/ext/f2c_math/Makefile.am
@@ -1,4 +1,5 @@
 cc_sources = \
+daux.c   \
 mach.cpp \
 ddaspk.c \
 dgbefa.c \