diff --git a/src/state.c b/src/state.c
index c6f85ef..95abdcb 100644
--- a/src/state.c
+++ b/src/state.c
@@ -281,7 +281,7 @@ void state_apply_event(SharedContext *context, const StateConfig *state_config,
   }
 }
 
-void state_apply(SharedContext *context, const StateConfig *state_config,
+void state_apply(const SharedContext *context, const StateConfig *state_config,
                  const MidiDevice *midi) {
   if (!midi->error) {
     update_values(context, state_config, midi);
diff --git a/src/state.h b/src/state.h
index 2ad1df8..fe0da1a 100644
--- a/src/state.h
+++ b/src/state.h
@@ -21,7 +21,7 @@ void state_reset(SharedContext *context);
 
 void state_randomize(SharedContext *context, const StateConfig *state_config);
 
-void state_apply(SharedContext *context, const StateConfig *state_config,
+void state_apply(const SharedContext *context, const StateConfig *state_config,
                  const MidiDevice *midi);
 
 void state_save(const SharedContext *context, const StateConfig *state_config,