diff --git a/tools/db_bench_tool.cc b/tools/db_bench_tool.cc
index 6f36b6d41..91d32e372 100644
--- a/tools/db_bench_tool.cc
+++ b/tools/db_bench_tool.cc
@@ -1644,7 +1644,7 @@ static enum DistributionType StringToDistributionType(const char* ctype) {
     return kNormal;
 
   fprintf(stdout, "Cannot parse distribution type '%s'\n", ctype);
-  return kFixed;  // default value
+  exit(1);
 }
 
 class BaseDistribution {
@@ -8119,6 +8119,7 @@ int db_bench_tool(int argc, char** argv) {
   else {
     fprintf(stdout, "Unknown compaction fadvice:%s\n",
             FLAGS_compaction_fadvice.c_str());
+    exit(1);
   }
 
   FLAGS_value_size_distribution_type_e =