diff --git a/include/cantera/tpx/utils.h b/include/cantera/tpx/utils.h
index 3c348b856..ca9427d3b 100644
--- a/include/cantera/tpx/utils.h
+++ b/include/cantera/tpx/utils.h
@@ -1,6 +1,8 @@
 #ifndef TPX_UTILS_H
 #define TPX_UTILS_H
 
+#include "cantera/tpx/Sub.h"
+
 namespace tpx
 {
 Substance* GetSub(int isub);
diff --git a/src/tpx/subs.h b/src/tpx/subs.h
deleted file mode 100755
index 7bb8c9080..000000000
--- a/src/tpx/subs.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#ifndef TPX_SUBS_H
-#define TPX_SUBS_H
-
-#include "CarbonDioxide.h"
-#include "Heptane.h"
-#include "HFC134a.h"
-#include "Hydrogen.h"
-#include "Methane.h"
-#include "Nitrogen.h"
-#include "Oxygen.h"
-#include "Water.h"
-#include "RedlichKwong.h"
-
-#endif
-
diff --git a/src/tpx/utils.cpp b/src/tpx/utils.cpp
index ebfcd207c..8082ffb71 100644
--- a/src/tpx/utils.cpp
+++ b/src/tpx/utils.cpp
@@ -1,6 +1,15 @@
-#include "subs.h"
 #include "cantera/tpx/utils.h"
 
+#include "CarbonDioxide.h"
+#include "Heptane.h"
+#include "HFC134a.h"
+#include "Hydrogen.h"
+#include "Methane.h"
+#include "Nitrogen.h"
+#include "Oxygen.h"
+#include "Water.h"
+#include "RedlichKwong.h"
+
 using std::string;
 
 namespace tpx
@@ -68,4 +77,3 @@ Substance* GetSub(int isub)
 }
 
 }
-