diff --git a/cpp/Matrix.cpp b/cpp/Matrix.cpp
index acb681751..f88ad8029 100644
--- a/cpp/Matrix.cpp
+++ b/cpp/Matrix.cpp
@@ -84,7 +84,7 @@ Matrix diag(const Vector& v) {
 }
 
 /* ************************************************************************* */
-/** Check if two matrizes are the same                                       */
+/** Check if two matrices are the same                                       */
 /* ************************************************************************* */
 bool equal_with_abs_tol(const Matrix& A, const Matrix& B, double tol) {
 
@@ -94,9 +94,12 @@ bool equal_with_abs_tol(const Matrix& A, const Matrix& B, double tol) {
   if(m1!=m2 || n1!=n2) return false;
 
   for(size_t i=0; i<m1; i++)
-    for(size_t j=0; j<n1; j++)
-      if(fabs(A(i,j) - B(i,j)) > tol)
-	return false;
+	  for(size_t j=0; j<n1; j++) {
+		  if(isnan(A(i,j)) xor isnan(B(i,j)))
+			  return false;
+		  if(fabs(A(i,j) - B(i,j)) > tol)
+			  return false;
+	  }
 
   return true;
 }
diff --git a/cpp/testMatrix.cpp b/cpp/testMatrix.cpp
index 0874a76d4..eb8dc84c7 100644
--- a/cpp/testMatrix.cpp
+++ b/cpp/testMatrix.cpp
@@ -172,6 +172,23 @@ TEST( matrix, equal )
   CHECK(A!=A3);
 }
 
+/* ************************************************************************* */
+TEST( matrix, equal_nan )
+{
+  Matrix A(4,4);
+  A(0,0) = -1; A(0,1) = 1; A(0,2)= 2; A(0,3)= 3;
+  A(1,0) =  1; A(1,1) =-3; A(1,2)= 1; A(1,3)= 3;
+  A(2,0) =  1; A(2,1) = 2; A(2,2)=-1; A(2,3)= 4;
+  A(3,0) =  2; A(3,1) = 1; A(3,2)= 2; A(3,3)=-2;
+
+  Matrix A2(A);
+
+  Matrix A3(A);
+  A3(3,3)=0.0/0.0;
+
+  CHECK(A!=A3);
+}
+
 /* ************************************************************************* */
 TEST( matrix, addition )
 {
diff --git a/cpp/testVector.cpp b/cpp/testVector.cpp
index 74400172d..0226e38a7 100644
--- a/cpp/testVector.cpp
+++ b/cpp/testVector.cpp
@@ -209,8 +209,6 @@ TEST( TestVector, equals )
 	Vector v1 = Vector_(1, 0.0/0.0); //testing nan
 	Vector v2 = Vector_(1, 1.0);
 	double tol = 1.;
-	print(v1, "v1");
-	print(v2, "v2");
 	CHECK(!equal_with_abs_tol(v1, v2, tol));
 }