diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 689fa6868..6bd22ee6e 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -55,6 +55,10 @@ This is a minor release: It combines bug fixes and new features.
   Changes to existing features were made in a backwards-compatible
   way such as to allow drop-in replacement of the v3.1[.1] JAR file.
 ">
+      <action dev="tn" type="fix" issue="MATH-862">
+        AbstractRealMatrix will now check for rectangular input arrays in
+        its copySubMatrix methods.
+      </action>
       <action dev="erans" type="fix" issue="MATH-949">
         Increment iteration counter in optimization algorithms.
       </action>
diff --git a/src/main/java/org/apache/commons/math3/linear/AbstractRealMatrix.java b/src/main/java/org/apache/commons/math3/linear/AbstractRealMatrix.java
index 432d9ede8..c3c9c2d2a 100644
--- a/src/main/java/org/apache/commons/math3/linear/AbstractRealMatrix.java
+++ b/src/main/java/org/apache/commons/math3/linear/AbstractRealMatrix.java
@@ -353,6 +353,13 @@ public abstract class AbstractRealMatrix
                                                        rowsCount, columnsCount);
         }
 
+        for (int i = 1; i < rowsCount; i++) {
+            if (destination[i].length != columnsCount) {
+                throw new MatrixDimensionMismatchException(destination.length, destination[i].length,
+                                                           rowsCount, columnsCount);
+            }
+        }
+
         walkInOptimizedOrder(new DefaultRealMatrixPreservingVisitor() {
 
             /** Initial row index. */
@@ -385,14 +392,19 @@ public abstract class AbstractRealMatrix
         throws OutOfRangeException, NullArgumentException, NoDataException,
         MatrixDimensionMismatchException {
         MatrixUtils.checkSubMatrixIndex(this, selectedRows, selectedColumns);
+        final int nCols = selectedColumns.length;
         if ((destination.length < selectedRows.length) ||
-            (destination[0].length < selectedColumns.length)) {
+            (destination[0].length < nCols)) {
             throw new MatrixDimensionMismatchException(destination.length, destination[0].length,
                                                        selectedRows.length, selectedColumns.length);
         }
 
         for (int i = 0; i < selectedRows.length; i++) {
             final double[] destinationI = destination[i];
+            if (destinationI.length != nCols) {
+                throw new MatrixDimensionMismatchException(destination.length, destinationI.length,
+                                                           selectedRows.length, selectedColumns.length);
+            }
             for (int j = 0; j < selectedColumns.length; j++) {
                 destinationI[j] = getEntry(selectedRows[i], selectedColumns[j]);
             }
diff --git a/src/test/java/org/apache/commons/math3/linear/Array2DRowRealMatrixTest.java b/src/test/java/org/apache/commons/math3/linear/Array2DRowRealMatrixTest.java
index 880fa3b2f..19cad4991 100644
--- a/src/test/java/org/apache/commons/math3/linear/Array2DRowRealMatrixTest.java
+++ b/src/test/java/org/apache/commons/math3/linear/Array2DRowRealMatrixTest.java
@@ -537,6 +537,11 @@ public final class Array2DRowRealMatrixTest {
         checkCopy(m, null,  1, 0, 2, 4, true);
         checkCopy(m, null, new int[] {},    new int[] { 0 }, true);
         checkCopy(m, null, new int[] { 0 }, new int[] { 4 }, true);
+        
+        // rectangular check
+        double[][] copy = new double[][] { { 0, 0, 0 }, { 0, 0 } };
+        checkCopy(m, copy, 0, 1, 0, 2, true);
+        checkCopy(m, copy, new int[] { 0, 1 }, new int[] { 0, 2 }, true);
     }
 
     private void checkCopy(RealMatrix m, double[][] reference,
@@ -544,8 +549,7 @@ public final class Array2DRowRealMatrixTest {
                            boolean mustFail) {
         try {
             double[][] sub = (reference == null) ?
-                             new double[1][1] :
-                             new double[reference.length][reference[0].length];
+                             new double[1][1] : createIdenticalCopy(reference);
             m.copySubMatrix(startRow, endRow, startColumn, endColumn, sub);
             Assert.assertEquals(new Array2DRowRealMatrix(reference), new Array2DRowRealMatrix(sub));
             if (mustFail) {
@@ -563,6 +567,10 @@ public final class Array2DRowRealMatrixTest {
             if (!mustFail) {
                 throw e;
             }
+        } catch (MatrixDimensionMismatchException e) {
+            if (!mustFail) {
+                throw e;
+            }
         }
     }
 
@@ -571,8 +579,7 @@ public final class Array2DRowRealMatrixTest {
                            boolean mustFail) {
         try {
             double[][] sub = (reference == null) ?
-                    new double[1][1] :
-                    new double[reference.length][reference[0].length];
+                    new double[1][1] : createIdenticalCopy(reference);
             m.copySubMatrix(selectedRows, selectedColumns, sub);
             Assert.assertEquals(new Array2DRowRealMatrix(reference), new Array2DRowRealMatrix(sub));
             if (mustFail) {
@@ -590,9 +597,21 @@ public final class Array2DRowRealMatrixTest {
             if (!mustFail) {
                 throw e;
             }
+        } catch (MatrixDimensionMismatchException e) {
+            if (!mustFail) {
+                throw e;
+            }
         }
     }
 
+    private double[][] createIdenticalCopy(final double[][] matrix) {
+        final double[][] matrixCopy = new double[matrix.length][];
+        for (int i = 0; i < matrixCopy.length; i++) {
+            matrixCopy[i] = new double[matrix[i].length];
+        }
+        return matrixCopy;
+    }
+
     @Test
     public void testGetRowMatrix() {
         RealMatrix m = new Array2DRowRealMatrix(subTestData);