diff --git a/src/training/unicharset/lstmtrainer.cpp b/src/training/unicharset/lstmtrainer.cpp
index a774b5f7beab6e5042d7895f2cda16a394debf09..b608942e4cd60f22db138d29e1a42b4e2c7f5e55 100644
--- a/src/training/unicharset/lstmtrainer.cpp
+++ b/src/training/unicharset/lstmtrainer.cpp
@@ -105,6 +105,10 @@ bool LSTMTrainer::TryLoadingCheckpoint(const char *filename, const char *old_tra
   if (!ReadTrainingDump(data, *this)) {
     return false;
   }
+  if (IsIntMode()) {
+    tprintf("Error, %s is an integer (fast) model, cannot continue training\n", filename);
+    return false;
+  }
   if (((old_traineddata == nullptr || *old_traineddata == '\0') &&
        network_->NumOutputs() == recoder_.code_range()) ||
       filename == old_traineddata) {