diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a01892ae..5f68a4ff 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -44,7 +44,7 @@ jobs:
           echo "::set-output name=flags::--ignore-platform-reqs"
 
       - name: Install dependencies
-        run: composer install --no-progress --prefer-dist --optimize-autoloader ${{ steps.composer-lock.outputs.flags }}
+        run: composer update --no-progress --prefer-dist --optimize-autoloader ${{ steps.composer-lock.outputs.flags }}
 
       - name: Setup problem matchers for PHP
         run: echo "::add-matcher::${{ runner.tool_cache }}/php.json"
diff --git a/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php b/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
index 4aecff73..6db17c28 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
@@ -240,11 +240,11 @@ class LUDecomposition
     /**
      * Solve A*X = B.
      *
-     * @param mixed $B a Matrix with as many rows as A and any number of columns
+     * @param Matrix $B a Matrix with as many rows as A and any number of columns
      *
      * @return Matrix X so that L*U*X = B(piv,:)
      */
-    public function solve($B)
+    public function solve(Matrix $B)
     {
         if ($B->getRowDimension() == $this->m) {
             if ($this->isNonsingular()) {
diff --git a/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php b/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
index 3bb8a10e..027706c1 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
@@ -205,7 +205,7 @@ class QRDecomposition
      *
      * @return Matrix matrix that minimizes the two norm of Q*R*X-B
      */
-    public function solve($B)
+    public function solve(Matrix $B)
     {
         if ($B->getRowDimension() == $this->m) {
             if ($this->isFullRank()) {