diff --git a/CMakeLists.txt b/CMakeLists.txt
index beb9206a..db103b6f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -420,18 +420,7 @@ set_property(SOURCE ${STA_SWIG_FILE}
   PROPERTY SWIG_FLAGS
   -module sta
   -namespace -prefix sta
-  -I${STA_HOME}/dcalc
-  -I${STA_HOME}/graph
-  -I${STA_HOME}/liberty
-  -I${STA_HOME}/network
-  -I${STA_HOME}/sdc
-  -I${STA_HOME}/sdf
-  -I${STA_HOME}/parasitics
-  -I${STA_HOME}/power
-  -I${STA_HOME}/search
-  -I${STA_HOME}/spice
-  -I${STA_HOME}/tcl
-  -I${STA_HOME}/verilog
+  -I${STA_HOME}
 )
 
 set(SWIG_FILES
@@ -469,7 +458,6 @@ set_source_files_properties(${STA_SWIG_CXX_FILE}
   # No simple way to modify the swig template that emits code full of warnings
   # so suppress them.
   COMPILE_OPTIONS "-Wno-cast-qual;-Wno-missing-braces;-Wno-deprecated-declarations"
-  INCLUDE_DIRECTORIES "${CUDD_INCLUDE}"
   )
 
 target_link_libraries(sta_swig
diff --git a/app/StaApp.i b/app/StaApp.i
index aad4502a..cc9168fd 100644
--- a/app/StaApp.i
+++ b/app/StaApp.i
@@ -17,17 +17,17 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 %include "Exception.i"
-%include "StaTclTypes.i"
-%include "Graph.i"
-%include "StaTcl.i"
-%include "Liberty.i"
-%include "Verilog.i"
-%include "Network.i"
-%include "NetworkEdit.i"
-%include "Sdf.i"
-%include "Sdc.i"
-%include "DelayCalc.i"
-%include "WriteSpice.i"
-%include "Parasitics.i"
-%include "Search.i"
-%include "Power.i"
+%include "tcl/StaTclTypes.i"
+%include "tcl/StaTcl.i"
+%include "dcalc/DelayCalc.i"
+%include "graph/Graph.i"
+%include "liberty/Liberty.i"
+%include "network/Network.i"
+%include "network/NetworkEdit.i"
+%include "parasitics/Parasitics.i"
+%include "power/Power.i"
+%include "sdc/Sdc.i"
+%include "sdf/Sdf.i"
+%include "search/Search.i"
+%include "spice/WriteSpice.i"
+%include "verilog/Verilog.i"
diff --git a/app/StaMain.cc b/app/StaMain.cc
index 2805afbe..5c1be7e9 100644
--- a/app/StaMain.cc
+++ b/app/StaMain.cc
@@ -140,4 +140,12 @@ unencode(const char *inits[])
   return unencoded;
 }
 
+// Hack until c++17 filesystem is better supported.
+bool
+is_regular_file(const char *filename)
+{
+  struct stat sb;
+  return stat(filename, &sb) == 0 && S_ISREG(sb.st_mode);
+}
+
 } // namespace
diff --git a/include/sta/Bdd.hh b/include/sta/Bdd.hh
index 1db20d74..0087fde6 100644
--- a/include/sta/Bdd.hh
+++ b/include/sta/Bdd.hh
@@ -18,10 +18,12 @@
 
 #include <map>
 
-#include "cudd.h"
 #include "StaState.hh"
 #include "LibertyClass.hh"
 
+struct DdNode;
+struct DdManager;
+
 namespace sta {
 
 typedef std::map<const LibertyPort*, DdNode*> BddPortVarMap;
diff --git a/include/sta/StaMain.hh b/include/sta/StaMain.hh
index 66ae11a6..f576aa0a 100644
--- a/include/sta/StaMain.hh
+++ b/include/sta/StaMain.hh
@@ -64,5 +64,7 @@ sourceTclFile(const char *filename,
 	      bool echo,
 	      bool verbose,
 	      Tcl_Interp *interp);
+bool
+is_regular_file(const char *filename);
 
 } // namespace
diff --git a/power/Power.cc b/power/Power.cc
index 10af008d..93f4cd59 100644
--- a/power/Power.cc
+++ b/power/Power.cc
@@ -19,6 +19,7 @@
 #include <algorithm> // max
 #include <cmath>     // abs
 
+#include "cudd.h"
 #include "Debug.hh"
 #include "EnumNameMap.hh"
 #include "Hash.hh"