diff --git a/ext/Makefile.am b/ext/Makefile.am
index 663468361..1bbdd8013 100644
--- a/ext/Makefile.am
+++ b/ext/Makefile.am
@@ -1,4 +1,4 @@
-SUBDIRS =  f2c_libs f2c_blas f2c_lapack cvode libexecstream
+SUBDIRS =   libexecstream f2c_math f2c_libs f2c_blas f2c_lapack cvode
 
 # header file accumulation                                                                                                 
 all:
diff --git a/ext/libexecstream/Makefile.am b/ext/libexecstream/Makefile.am
index ac4f1b59f..141ec3307 100644
--- a/ext/libexecstream/Makefile.am
+++ b/ext/libexecstream/Makefile.am
@@ -1,5 +1,5 @@
-cc_sources              = exec-stream.h
-h_sources               = 
+cc_sources              = exec-stream.cpp
+h_sources               = exec-stream.h
 
 AM_CPPFLAGS             = -I.
 AM_CXXFLAGS             = $(AM_CPPFLAGS)