diff --git a/MultiSource/Applications/siod/CMakeLists.txt b/MultiSource/Applications/siod/CMakeLists.txt
--- a/MultiSource/Applications/siod/CMakeLists.txt
+++ b/MultiSource/Applications/siod/CMakeLists.txt
@@ -1,5 +1,5 @@
 list(APPEND CPPFLAGS -D__USE_MISC -D__USE_GNU -D__USE_SVID -D__USE_XOPEN_EXTENDED -D__USE_XOPEN -Dunix)
-list(APPEND CFLAGS -Wno-implicit-function-declaration -Wno-implicit-int)
+list(APPEND CFLAGS -Wno-implicit-function-declaration -Wno-implicit-int -Wno-int-conversion)
 list(APPEND LDFLAGS -lm)
 set(RUN_OPTIONS -v1 test.scm)
 llvm_multisource(siod)
diff --git a/MultiSource/Applications/siod/Makefile b/MultiSource/Applications/siod/Makefile
--- a/MultiSource/Applications/siod/Makefile
+++ b/MultiSource/Applications/siod/Makefile
@@ -1,7 +1,7 @@
 LEVEL = ../../..
 PROG     = siod
 CPPFLAGS = -D__USE_MISC -D__USE_GNU -D__USE_SVID -D__USE_XOPEN_EXTENDED -D__USE_XOPEN -Dunix
-CFLAGS += -Wno-implicit-function-declaration -Wno-implicit-int
+CFLAGS += -Wno-implicit-function-declaration -Wno-implicit-int -Wno-int-conversion
 LDFLAGS  = -lm $(TOOLLINKOPTS)
 
 RUN_OPTIONS = -v1 $(PROJ_SRC_DIR)/test.scm