diff --git a/tests/Map/put.php b/tests/Map/put.php
index c09a9f1..cf2eb8c 100644
--- a/tests/Map/put.php
+++ b/tests/Map/put.php
@@ -31,6 +31,11 @@ public function putDataProvider()
                 [[null, null], [null, null]],
                 [[null, null]]
             ],
+            [
+                // Test that -0.0 and 0.0 map to the same key
+                [[-0.0, -0.0], [0.0, 0.0]],
+                [[-0.0, 0.0]],
+            ]
         ];
     }
 
diff --git a/tests/Set/add.php b/tests/Set/add.php
index c114079..ad33190 100644
--- a/tests/Set/add.php
+++ b/tests/Set/add.php
@@ -23,6 +23,9 @@ public function addDataProvider()
             [['1'], [ 1 ], ['1', 1 ]],
             [[ 1 ], ['1'], [ 1, '1']],
 
+            // Test that 0.0 and -0.0 are treated as the same value
+            [[], [0.0, -0.0], [0.0]],
+
             // Test adding sample values to empty set adds all.
             [[], $unique, $unique],