diff --git a/CHANGES.md b/CHANGES.md
index bbc63ea..f026aff 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,6 @@
+# 0.12.1 (2024-01-12)
+
+* fix invalid nodata overwriting
 
 # 0.12.0 (2024-01-12)
 
diff --git a/rio_viz/app.py b/rio_viz/app.py
index 83043aa..dafa64b 100644
--- a/rio_viz/app.py
+++ b/rio_viz/app.py
@@ -216,7 +216,7 @@ def statistics(
         ):
             """Handle /stats requests."""
             with self.reader(self.src_path) as src_dst:
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type
@@ -247,7 +247,7 @@ def point(
             """Handle /point requests."""
             lon, lat = list(map(float, coordinates.split(",")))
             with self.reader(self.src_path) as src_dst:  # type: ignore
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type
@@ -289,7 +289,7 @@ def preview(
         ):
             """Handle /preview requests."""
             with self.reader(self.src_path) as src_dst:  # type: ignore
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type
@@ -361,7 +361,7 @@ def part(
         ):
             """Create image from part of a dataset."""
             with self.reader(self.src_path) as src_dst:  # type: ignore
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type
@@ -423,7 +423,7 @@ def geojson_part(
         ):
             """Handle /feature requests."""
             with self.reader(self.src_path) as src_dst:  # type: ignore
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type
@@ -510,7 +510,7 @@ def tile(
             tilesize = tilesize or default_tilesize
 
             with self.reader(self.src_path) as src_dst:  # type: ignore
-                if self.nodata is not None and dataset_params.nodata is not None:
+                if self.nodata is not None and dataset_params.nodata is None:
                     dataset_params.nodata = self.nodata
 
                 # Adapt options for each reader type