diff --git a/src/pyhpp_plot/__init__.py b/src/pyhpp_plot/__init__.py
index 67b95f1..0ae0f11 100644
--- a/src/pyhpp_plot/__init__.py
+++ b/src/pyhpp_plot/__init__.py
@@ -1,9 +1,3 @@
-from .graph_viewer import (
-    MenuActionProxy,
-    show_graph,
-    show_graph_blocking,
-    show_interactive_graph,
-)
 from .graph_viewer_thread import GraphViewerThread
 from .interactive_viewer import InteractiveGraphViewer
 from .websocket_bridge import GraphWebSocketBridge
@@ -12,8 +6,26 @@
     "GraphViewerThread",
     "GraphWebSocketBridge",
     "InteractiveGraphViewer",
-    "MenuActionProxy",
-    "show_graph",
-    "show_graph_blocking",
-    "show_interactive_graph",
 ]
+
+try:
+    # `graph_viewer` is a Boost.Python extension module built only when
+    # hpp-plot is compiled with -DUSE_QT=ON (see CMakeLists.txt). It is not
+    # required by the recommended pyhpp_plot workflow (GraphViewerThread /
+    # InteractiveGraphViewer / GraphWebSocketBridge), so its absence must not
+    # prevent `import pyhpp_plot` from succeeding when built with USE_QT=OFF.
+    from .graph_viewer import (
+        MenuActionProxy,
+        show_graph,
+        show_graph_blocking,
+        show_interactive_graph,
+    )
+
+    __all__ += [
+        "MenuActionProxy",
+        "show_graph",
+        "show_graph_blocking",
+        "show_interactive_graph",
+    ]
+except ImportError:
+    pass