diff --git a/src/common_gdbus.cpp b/src/common_gdbus.cpp
index b297f37..1893a9e 100644
--- a/src/common_gdbus.cpp
+++ b/src/common_gdbus.cpp
@@ -82,7 +82,7 @@ variant_type::variant_type(const std::type_info& primitive) {
     else if(primitive == typeid(bool))
         type = G_VARIANT_TYPE_BOOLEAN;
     else
-        assert(!"Invalid GVariant type");
+        throw std::runtime_error("Invalid GVariant type");
     data = g_type_to_any(g_variant_type_copy(type));
 }
 
diff --git a/src/server_gdbus.cpp b/src/server_gdbus.cpp
index 3eee1fb..9d7bfca 100644
--- a/src/server_gdbus.cpp
+++ b/src/server_gdbus.cpp
@@ -293,7 +293,7 @@ struct server::internal {
             return g_variant_new_array(nullptr, raw_array.get(), map.size());
         } else {
             // This should not happen
-            assert(!"converted unhandled variant type");
+            throw std::runtime_error("converted unhandled variant type");
         }
     }
 
@@ -478,6 +478,7 @@ struct server::internal {
                         G_DBUS_ERROR_FAILED,
                         "Internal error");
             assert(!"method call on non-existent server");
+            return nullptr;
         }
     }
 
@@ -564,8 +565,8 @@ struct server::internal {
                         G_DBUS_ERROR_FAILED,
                         "Internal error");
             assert(!"method call on non-existent server");
+            return false;
         }
-
     }
 
     static void name_acquired_handler(