diff --git a/armsrc/Makefile b/armsrc/Makefile
index f48111332..4eb4997d5 100644
--- a/armsrc/Makefile
+++ b/armsrc/Makefile
@@ -20,7 +20,7 @@ endif
 #in the next section to remove that particular feature from compilation.
 # NO space,TABs after the "\" sign.
 APP_CFLAGS = $(PLATFORM_DEFS) \
-             -ffunction-sections -fdata-sections
+             -ffunction-sections -fdata-sections -fno-common
 
 SRC_LF = lfops.c lfsampling.c pcf7931.c lfdemod.c lfadc.c
 SRC_ISO15693 = iso15693.c iso15693tools.c
diff --git a/armsrc/appmain.c b/armsrc/appmain.c
index d0d996770..9a1743b6b 100644
--- a/armsrc/appmain.c
+++ b/armsrc/appmain.c
@@ -83,8 +83,9 @@ static void umm_test(void) {
     umm_info(NULL, true);
     uint8_t* dest = (uint8_t*)umm_malloc(2000);    
     umm_free(dest);
+    umm_info(NULL, true);
     dest = (uint8_t*)umm_malloc(12000);  
-    umm_info(dest, true);
+    umm_info(NULL, true);
     umm_free(dest);
 }