diff --git a/src/Mutator/Arithmetic/DivEqual.php b/src/Mutator/Arithmetic/DivEqual.php
index bee24adb3..cf58ae96f 100644
--- a/src/Mutator/Arithmetic/DivEqual.php
+++ b/src/Mutator/Arithmetic/DivEqual.php
@@ -78,6 +78,27 @@ public function mutate(Node $node): iterable
 
     public function canMutate(Node $node): bool
     {
-        return $node instanceof Node\Expr\AssignOp\Div;
+        if (!$node instanceof Node\Expr\AssignOp\Div) {
+            return false;
+        }
+
+        if ($this->isNumericOne($node->expr)) {
+            return false;
+        }
+
+        if ($node->expr instanceof Node\Expr\UnaryMinus && $this->isNumericOne($node->expr->expr)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    private function isNumericOne(Node $node): bool
+    {
+        if ($node instanceof Node\Scalar\LNumber && $node->value === 1) {
+            return true;
+        }
+
+        return $node instanceof Node\Scalar\DNumber && $node->value === 1.0;
     }
 }
diff --git a/tests/phpunit/Mutator/Arithmetic/DivEqualTest.php b/tests/phpunit/Mutator/Arithmetic/DivEqualTest.php
index 423323a5e..ba35ff743 100644
--- a/tests/phpunit/Mutator/Arithmetic/DivEqualTest.php
+++ b/tests/phpunit/Mutator/Arithmetic/DivEqualTest.php
@@ -73,6 +73,46 @@ public function mutationsProvider(): iterable
 <?php
 
 $a = 10 / 2;
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate division by 1 to avoid an equivalent mutation' => [
+            <<<'PHP'
+<?php
+
+$a = 1;
+$a /= 1;
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate division by -1 to avoid an equivalent mutation' => [
+            <<<'PHP'
+<?php
+
+$a = 1;
+$a /= -1;
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate division by 1.0 to avoid an equivalent mutation' => [
+            <<<'PHP'
+<?php
+
+$a = 1;
+$a /= 1.0;
+PHP
+            ,
+        ];
+
+        yield 'It does not mutate division by -1.0 to avoid an equivalent mutation' => [
+            <<<'PHP'
+<?php
+
+$a = 1;
+$a /= -1.0;
 PHP
             ,
         ];