diff --git a/IncidenceMatrix.cc b/IncidenceMatrix.cc
index 286eb1a26cd277a912489378f9bd37791401b04a..3839a1ccc89982259af4a2368f6799447f29a19e 100644
--- a/IncidenceMatrix.cc
+++ b/IncidenceMatrix.cc
@@ -17,6 +17,8 @@
  * along with Dynare.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cstdlib>
+#include <cstring>
 
 #include "IncidenceMatrix.hh"
 
diff --git a/Makefile b/Makefile
index 1712c2ac9ee8f19e3b8d4dee735e6451279c78ef..204754aa8712add0d06742f124afd521884352e4 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ OBJS = \
 	ExprNode.o \
 	ModelNormalization.o \
 	ModelBlocks.o \
-    IncidenceMatrix.o \
+	IncidenceMatrix.o \
 	BlockTriangular.o \
 	Model_Graph.o \
 	SymbolGaussElim.o \