diff --git a/src/Numerics.IO/LinearAlgebra/IO/Matlab/MatlabParser.cs b/src/Numerics.IO/LinearAlgebra/IO/Matlab/MatlabParser.cs
index 4485d710..7c8cbdf6 100644
--- a/src/Numerics.IO/LinearAlgebra/IO/Matlab/MatlabParser.cs
+++ b/src/Numerics.IO/LinearAlgebra/IO/Matlab/MatlabParser.cs
@@ -412,7 +412,6 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
             for (var i = 0; i < ir.Count; i++)
             {
                 var row = ir[i];
-               // if (jc[col + 1] == i)
                 while(jc[col + 1] == i)
                 {
                     col++;
@@ -470,7 +469,7 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
             for (var i = 0; i < ir.Count; i++)
             {
                 var row = ir[i];
-                if (jc[col + 1] == i)
+                while (jc[col + 1] == i)
                 {
                     col++;
                 }
@@ -529,7 +528,7 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
             for (var i = 0; i < ir.Count; i++)
             {
                 var row = ir[i];
-                if (jc[col + 1] == i)
+                while (jc[col + 1] == i)
                 {
                     col++;
                 }
@@ -585,7 +584,7 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
                 for (var i = 0; i < ir.Count; i++)
                 {
                     var row = ir[i];
-                    if (jc[col + 1] == i)
+                    while (jc[col + 1] == i)
                     {
                         col++;
                     }
@@ -646,7 +645,7 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
             for (var i = 0; i < ir.Count; i++)
             {
                 var row = ir[i];
-                if (jc[col + 1] == i)
+                while (jc[col + 1] == i)
                 {
                     col++;
                 }
@@ -703,7 +702,7 @@ namespace MathNet.Numerics.LinearAlgebra.IO.Matlab
                 for (var i = 0; i < ir.Count; i++)
                 {
                     var row = ir[i];
-                    if (jc[col + 1] == i)
+                    while (jc[col + 1] == i)
                     {
                         col++;
                     }
diff --git a/src/UnitTests/LinearAlgebraTests/Complex/IO/MatlabWriterTests.cs b/src/UnitTests/LinearAlgebraTests/Complex/IO/MatlabWriterTests.cs
index 486251df..ad69ea87 100644
--- a/src/UnitTests/LinearAlgebraTests/Complex/IO/MatlabWriterTests.cs
+++ b/src/UnitTests/LinearAlgebraTests/Complex/IO/MatlabWriterTests.cs
@@ -97,16 +97,14 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Complex.IO
             }
 
             Matrix mat3 = new SparseMatrix(5, 4);
-            for (var i = 0; i < mat3.ColumnCount; i++)
-            {
-                mat3[i, i] = new Complex(i + .1, i + .1);
-            }
+            mat3[0, 0] = new Complex(1.1, 1.1);
+            mat3[0, 2] = new Complex(2.2, 2.2);
+            mat3[4, 3] = new Complex(3.3, 3.3);
 
             Matrix mat4 = new SparseMatrix(3, 5);
-            for (var i = 0; i < mat4.RowCount; i++)
-            {
-                mat4[i, i] = new Complex(i + .1, i + .1);
-            }
+            mat4[0, 0] = new Complex(1.1, 1.1);
+            mat4[0, 2] = new Complex(2.2, 2.2);
+            mat4[2, 4] = new Complex(3.3, 3.3);
 
             var write = new[] { mat1, mat2, mat3, mat4 };
 
diff --git a/src/UnitTests/LinearAlgebraTests/Complex32/IO/MatlabWriterTests.cs b/src/UnitTests/LinearAlgebraTests/Complex32/IO/MatlabWriterTests.cs
index c21d51d9..71aa7338 100644
--- a/src/UnitTests/LinearAlgebraTests/Complex32/IO/MatlabWriterTests.cs
+++ b/src/UnitTests/LinearAlgebraTests/Complex32/IO/MatlabWriterTests.cs
@@ -97,16 +97,14 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Complex32.IO
             }
 
             Matrix mat3 = new SparseMatrix(5, 4);
-            for (var i = 0; i < mat3.ColumnCount; i++)
-            {
-                mat3[i, i] = new Complex32(i + .1f, i + .1f);
-            }
+            mat3[0, 0] = new Complex32(1.1f, 1.1f);
+            mat3[0, 2] = new Complex32(2.2f, 2.2f);
+            mat3[4, 3] = new Complex32(3.3f, 3.3f);
 
             Matrix mat4 = new SparseMatrix(3, 5);
-            for (var i = 0; i < mat4.RowCount; i++)
-            {
-                mat4[i, i] = new Complex32(i + .1f, i + .1f);
-            }
+            mat4[0, 0] = new Complex32(1.1f, 1.1f);
+            mat4[0, 2] = new Complex32(2.2f, 2.2f);
+            mat4[2, 4] = new Complex32(3.3f, 3.3f);
 
             var write = new[] { mat1, mat2, mat3, mat4 };
 
diff --git a/src/UnitTests/LinearAlgebraTests/Double/IO/MatlabWriterTests.cs b/src/UnitTests/LinearAlgebraTests/Double/IO/MatlabWriterTests.cs
index 608d6ef1..f4c3c5db 100644
--- a/src/UnitTests/LinearAlgebraTests/Double/IO/MatlabWriterTests.cs
+++ b/src/UnitTests/LinearAlgebraTests/Double/IO/MatlabWriterTests.cs
@@ -96,16 +96,14 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Double.IO
             }
 
             Matrix mat3 = new SparseMatrix(5, 4);
-            for (var i = 0; i < mat3.ColumnCount; i++)
-            {
-                mat3[i, i] = i + .1;
-            }
+            mat3[0, 0] = 1.1;
+            mat3[0, 2] = 2.2;
+            mat3[4, 3] = 3.3;
 
             Matrix mat4 = new SparseMatrix(3, 5);
-            for (var i = 0; i < mat4.RowCount; i++)
-            {
-                mat4[i, i] = i + .1;
-            }
+            mat4[0, 0] = 1.1;
+            mat4[0, 2] = 2.2;
+            mat4[2, 4] = 3.3;
 
             var write = new[] { mat1, mat2, mat3, mat4 };
 
diff --git a/src/UnitTests/LinearAlgebraTests/Single/IO/MatlabWriterTests.cs b/src/UnitTests/LinearAlgebraTests/Single/IO/MatlabWriterTests.cs
index 3ded9446..694d002b 100644
--- a/src/UnitTests/LinearAlgebraTests/Single/IO/MatlabWriterTests.cs
+++ b/src/UnitTests/LinearAlgebraTests/Single/IO/MatlabWriterTests.cs
@@ -95,16 +95,14 @@ namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Single.IO
             }
 
             Matrix mat3 = new SparseMatrix(5, 4);
-            for (var i = 0; i < mat3.ColumnCount; i++)
-            {
-                mat3[i, i] = i + .1f;
-            }
+            mat3[0, 0] = 1.1f;
+            mat3[0, 2] = 2.2f;
+            mat3[4, 3] = 3.3f;
 
             Matrix mat4 = new SparseMatrix(3, 5);
-            for (var i = 0; i < mat4.RowCount; i++)
-            {
-                mat4[i, i] = i + .1f;
-            }
+            mat4[0, 0] = 1.1f;
+            mat4[0, 2] = 2.2f;
+            mat4[2, 4] = 3.3f;
 
             var write = new[] { mat1, mat2, mat3, mat4 };