diff --git a/Makefile b/Makefile
index 59af7a018..0f2fcc958 100644
--- a/Makefile
+++ b/Makefile
@@ -64,7 +64,7 @@ zlibwrapper:
 
 .PHONY: test
 test:
-	$(MAKE) -C $(PRGDIR) allVariants MOREFLAGS+="-g -DDEBUGLEVEL=1"
+	MOREFLAGS+="-g -DDEBUGLEVEL=1 -Werror" $(MAKE) -C $(PRGDIR) allVariants
 	$(MAKE) -C $(TESTDIR) $@
 
 .PHONY: shortest
diff --git a/programs/zstdcli.c b/programs/zstdcli.c
index be6204667..cc3ec26c6 100644
--- a/programs/zstdcli.c
+++ b/programs/zstdcli.c
@@ -441,7 +441,7 @@ int main(int argCount, const char* argv[])
 #endif
 
     /* preset behaviors */
-    if (exeNameMatch(programName, ZSTD_ZSTDMT)) nbWorkers=0;
+    if (exeNameMatch(programName, ZSTD_ZSTDMT)) nbWorkers=0, singleThread=0;
     if (exeNameMatch(programName, ZSTD_UNZSTD)) operation=zom_decompress;
     if (exeNameMatch(programName, ZSTD_CAT)) { operation=zom_decompress; forceStdout=1; FIO_overwriteMode(); outFileName=stdoutmark; g_displayLevel=1; }   /* supports multiple formats */
     if (exeNameMatch(programName, ZSTD_ZCAT)) { operation=zom_decompress; forceStdout=1; FIO_overwriteMode(); outFileName=stdoutmark; g_displayLevel=1; }  /* behave like zcat, also supports multiple formats */
@@ -764,7 +764,7 @@ int main(int argCount, const char* argv[])
         DISPLAYLEVEL(3, "Note: %d physical core(s) detected \n", nbWorkers);
     }
 #else
-    (void)singleThread;
+    (void)singleThread; (void)nbWorkers;
 #endif
 
 #ifdef UTIL_HAS_CREATEFILELIST