diff --git a/Source/Matrix.swift b/Source/Matrix.swift
index d974d4e2..cff0b579 100644
--- a/Source/Matrix.swift
+++ b/Source/Matrix.swift
@@ -38,14 +38,11 @@ public struct Matrix<Scalar> where Scalar: FloatingPoint, Scalar: ExpressibleByF
     }
 
     public init(_ contents: [[Scalar]]) {
-        let m: Int = contents.count
-        let n: Int = contents[0].count
-        let repeatedValue: Scalar = 0.0
-
-        self.init(rows: m, columns: n, repeatedValue: repeatedValue)
+        self.init(rows: contents.count, columns: contents[0].count, repeatedValue: 0.0)
 
         for (i, row) in contents.enumerated() {
-            grid.replaceSubrange(i*n ... i*n+Swift.min(m, row.count), with: row)
+            precondition(row.count == columns, "All rows should have the same number of columns")
+            grid.replaceSubrange(i*columns ..< (i + 1)*columns, with: row)
         }
     }
 
diff --git a/Tests/SurgeTests/MatrixTests.swift b/Tests/SurgeTests/MatrixTests.swift
index 9fa5e186..9bededb0 100644
--- a/Tests/SurgeTests/MatrixTests.swift
+++ b/Tests/SurgeTests/MatrixTests.swift
@@ -27,8 +27,11 @@ class MatrixTests: XCTestCase {
     var matrix : Matrix<Double> = Matrix<Double>([[1, 2, 3, 4], [5,6,7,8], [9, 10, 11, 12]])
 
     func testInit() {
-        let m = Matrix([[1.0, 2.0]])
-        XCTAssertEqual(m.grid, [1.0, 2.0])
+        let m1 = Matrix([[1.0, 2.0]])
+        XCTAssertEqual(m1.grid, [1.0, 2.0])
+
+        let m2 = Matrix([[1, 1], [1, -1]])
+        XCTAssertEqual(m2.grid, [1, 1, 1, -1])
     }
 
     func testSubscriptRow() {