diff --git a/src/runtime/c/Makefile.am b/src/runtime/c/Makefile.am
index 213be21e2..07dbe5f42 100644
--- a/src/runtime/c/Makefile.am
+++ b/src/runtime/c/Makefile.am
@@ -3,21 +3,21 @@ lib_LTLIBRARIES = libpgf.la
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libpgf.pc
 
-pgfincludedir=$(includedir)
+pgfincludedir=$(includedir)/pgf
 pgfinclude_HEADERS = \
-	pgf.h
+	pgf/pgf.h
 
 libpgf_la_SOURCES = \
-	db.cxx \
-	db.h \
-	text.cxx \
-	text.h \
-	pgf.cxx \
-	reader.cxx \
-	reader.h \
-	data.h \
-	expr.h \
-	namespace.h
+	pgf/db.cxx \
+	pgf/db.h \
+	pgf/text.cxx \
+	pgf/text.h \
+	pgf/pgf.cxx \
+	pgf/reader.cxx \
+	pgf/reader.h \
+	pgf/data.h \
+	pgf/expr.h \
+	pgf/namespace.h
 
 libpgf_la_LDFLAGS = "-no-undefined"
 
diff --git a/src/runtime/c/data.h b/src/runtime/c/pgf/data.h
similarity index 100%
rename from src/runtime/c/data.h
rename to src/runtime/c/pgf/data.h
diff --git a/src/runtime/c/db.cxx b/src/runtime/c/pgf/db.cxx
similarity index 100%
rename from src/runtime/c/db.cxx
rename to src/runtime/c/pgf/db.cxx
diff --git a/src/runtime/c/db.h b/src/runtime/c/pgf/db.h
similarity index 100%
rename from src/runtime/c/db.h
rename to src/runtime/c/pgf/db.h
diff --git a/src/runtime/c/expr.h b/src/runtime/c/pgf/expr.h
similarity index 100%
rename from src/runtime/c/expr.h
rename to src/runtime/c/pgf/expr.h
diff --git a/src/runtime/c/namespace.h b/src/runtime/c/pgf/namespace.h
similarity index 100%
rename from src/runtime/c/namespace.h
rename to src/runtime/c/pgf/namespace.h
diff --git a/src/runtime/c/pgf.cxx b/src/runtime/c/pgf/pgf.cxx
similarity index 100%
rename from src/runtime/c/pgf.cxx
rename to src/runtime/c/pgf/pgf.cxx
diff --git a/src/runtime/c/pgf.h b/src/runtime/c/pgf/pgf.h
similarity index 100%
rename from src/runtime/c/pgf.h
rename to src/runtime/c/pgf/pgf.h
diff --git a/src/runtime/c/reader.cxx b/src/runtime/c/pgf/reader.cxx
similarity index 100%
rename from src/runtime/c/reader.cxx
rename to src/runtime/c/pgf/reader.cxx
diff --git a/src/runtime/c/reader.h b/src/runtime/c/pgf/reader.h
similarity index 100%
rename from src/runtime/c/reader.h
rename to src/runtime/c/pgf/reader.h
diff --git a/src/runtime/c/text.cxx b/src/runtime/c/pgf/text.cxx
similarity index 100%
rename from src/runtime/c/text.cxx
rename to src/runtime/c/pgf/text.cxx
diff --git a/src/runtime/c/text.h b/src/runtime/c/pgf/text.h
similarity index 100%
rename from src/runtime/c/text.h
rename to src/runtime/c/pgf/text.h
diff --git a/src/runtime/c/vector.h b/src/runtime/c/pgf/vector.h
similarity index 100%
rename from src/runtime/c/vector.h
rename to src/runtime/c/pgf/vector.h
diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index 93eebaf22..fd97dc2bd 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -41,7 +41,7 @@ import Data.Typeable
 import qualified Data.Map as Map
 import Data.IORef
 
-#include <pgf.h>
+#include <pgf/pgf.h>
 
 type AbsName  = String -- ^ Name of abstract syntax
 type ConcName = String -- ^ Name of concrete syntax
diff --git a/src/runtime/haskell/PGF2/FFI.hsc b/src/runtime/haskell/PGF2/FFI.hsc
index 47f7b269c..f451cb25f 100644
--- a/src/runtime/haskell/PGF2/FFI.hsc
+++ b/src/runtime/haskell/PGF2/FFI.hsc
@@ -9,7 +9,7 @@ import Foreign.Ptr
 import Foreign.ForeignPtr
 import qualified Data.Map as Map
 
-#include <pgf.h>
+#include <pgf/pgf.h>
 
 -- | An abstract data type representing multilingual grammar
 -- in Portable Grammar Format.
diff --git a/src/runtime/haskell/pgf2.cabal b/src/runtime/haskell/pgf2.cabal
index 2b1eaef4f..b16b383b7 100644
--- a/src/runtime/haskell/pgf2.cabal
+++ b/src/runtime/haskell/pgf2.cabal
@@ -25,7 +25,6 @@ library
 
   extra-libraries:     pgf
   cc-options:          -std=c99
-  c-sources:           utils.c
 
 test-suite basic
   type:       exitcode-stdio-1.0
diff --git a/src/runtime/python/pypgf.c b/src/runtime/python/pypgf.c
index d4b9b0f02..6c145b3be 100644
--- a/src/runtime/python/pypgf.c
+++ b/src/runtime/python/pypgf.c
@@ -2,7 +2,7 @@
 #include <Python.h>
 #include "structmember.h"
 
-#include <pgf.h>
+#include <pgf/pgf.h>
 
 #if PY_MAJOR_VERSION >= 3
 	#define PyIntObject                  PyLongObject
@@ -3521,7 +3521,7 @@ pgf_readPGF(PyObject *self, PyObject *args)
 		return NULL;
     } else if (err.type == PGF_EXN_PGF_ERROR) {
         PyErr_SetString(PGFError, err.msg);
-        free(err.msg);
+        free((char*) err.msg);
 		Py_DECREF(py_pgf);
 		return NULL;
 	}