diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae78708..2d98da2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 ## 1.13.0
 
 * feat: `Map(property: null)` ignores the mapping
+* fix: only remove source property mapping if it maps to the same name on the
+  target side
 
 ## 1.12.0
 
diff --git a/src/Transformer/MetadataUtil/PropertyMappingResolver/PropertyMappingResolver.php b/src/Transformer/MetadataUtil/PropertyMappingResolver/PropertyMappingResolver.php
index 1525255..f068715 100644
--- a/src/Transformer/MetadataUtil/PropertyMappingResolver/PropertyMappingResolver.php
+++ b/src/Transformer/MetadataUtil/PropertyMappingResolver/PropertyMappingResolver.php
@@ -69,7 +69,7 @@ class: $sourceClass,
             }
 
             if ($targetProperty === null) {
-                if (isset($targetPropertyToSourceProperty[$sourceProperty])) {
+                if (($targetPropertyToSourceProperty[$sourceProperty] ?? null) === $sourceProperty) {
                     unset($targetPropertyToSourceProperty[$sourceProperty]);
                 }