diff --git a/include/dbcppp/CApi.h b/include/dbcppp/CApi.h
index 18f70de6..24c22a0b 100644
--- a/include/dbcppp/CApi.h
+++ b/include/dbcppp/CApi.h
@@ -242,7 +242,7 @@ extern "C"
     DBCPPP_API uint64_t dbcppp_SignalMultiplexerSwitchValue(const dbcppp_Signal* sig);
     DBCPPP_API uint64_t dbcppp_SignalMultiplexerValues_Size(const dbcppp_Signal* sig);
     DBCPPP_API const dbcppp_SignalMultiplexerValue* dbcppp_SignalMultiplexerValues_Get(const dbcppp_Signal* sig, uint64_t i);
-    DBCPPP_API const char* dbcppp_SignalMultiplexerValue_SwitchName(const dbcppp_SignalMultiplexerValue* mux_val, uint64_t i);
+    DBCPPP_API const char* dbcppp_SignalMultiplexerValue_SwitchName(const dbcppp_SignalMultiplexerValue* mux_val);
     DBCPPP_API uint64_t dbcppp_SignalMultiplexerValue_ValueRanges_Size(const dbcppp_SignalMultiplexerValue* mux_val);
     DBCPPP_API const dbcppp_ValueRange* dbcppp_SignalMultiplexerValue_ValueRanges_Get(const dbcppp_SignalMultiplexerValue* mux_val, uint64_t i);
     DBCPPP_API uint64_t dbcppp_SignalStartBit(const dbcppp_Signal* sig);
diff --git a/src/libdbcppp/CApi.cpp b/src/libdbcppp/CApi.cpp
index 24e495de..2cf8a1bb 100644
--- a/src/libdbcppp/CApi.cpp
+++ b/src/libdbcppp/CApi.cpp
@@ -889,7 +889,7 @@ extern "C"
         auto sigi = reinterpret_cast<const SignalImpl*>(sig);
         return reinterpret_cast<const dbcppp_SignalMultiplexerValue*>(&sigi->SignalMultiplexerValues_Get(i));
     }
-    DBCPPP_API const char* dbcppp_SignalMultiplexerValue_SwitchName(const dbcppp_SignalMultiplexerValue* mux_val, uint64_t i)
+    DBCPPP_API const char* dbcppp_SignalMultiplexerValue_SwitchName(const dbcppp_SignalMultiplexerValue* mux_val)
     {
         auto sigi = reinterpret_cast<const ISignalMultiplexerValue*>(mux_val);
         return sigi->SwitchName().c_str();