diff --git a/SDA.c b/SDA.c
index 08a7db2..b900fe8 100644
--- a/SDA.c
+++ b/SDA.c
@@ -15,6 +15,7 @@ ObjRef getSDA(int i, struct sda s) {
 }
 
 void setSDA(int point, ObjRef val, struct sda s) {
+    if (val == NULL) perror("Value is null");
     s.sda[point] = val;
 }
 
diff --git a/bigint/build/bin/testbip b/bigint/build/bin/testbip
index e440237..8ff35dc 100755
Binary files a/bigint/build/bin/testbip and b/bigint/build/bin/testbip differ
diff --git a/bigint/build/lib/libbigint.a b/bigint/build/lib/libbigint.a
index dd462db..f13c526 100644
Binary files a/bigint/build/lib/libbigint.a and b/bigint/build/lib/libbigint.a differ
diff --git a/bigint/src/libbigint.a b/bigint/src/libbigint.a
index dd462db..f13c526 100644
Binary files a/bigint/src/libbigint.a and b/bigint/src/libbigint.a differ
diff --git a/bigint/tst/testbip b/bigint/tst/testbip
index e440237..8ff35dc 100755
Binary files a/bigint/tst/testbip and b/bigint/tst/testbip differ
diff --git a/njvm.o b/njvm.o
index adbcd7b..59baaa5 100644
Binary files a/njvm.o and b/njvm.o differ
diff --git a/record.c b/record.c
index b6345db..e67ca85 100644
--- a/record.c
+++ b/record.c
@@ -20,29 +20,35 @@ ObjRef newRecord(int size){
     return record;
 }
 int getSize(ObjRef arr){
+    if(arr == NULL) return 0;
     return GET_ELEMENT_COUNT(arr);
 }
 ObjRef getField(ObjRef arr, int point){
+    if(arr == NULL) perror("Record is null");
     if(0 > point || point > getSize(arr)){
         printf("Index %i out of bounds for length %i\n",point, getSize(arr));
     }
     return *(ObjRef *)GET_REFS_PTR(arr)[point]->data;
 }
 void setField(ObjRef arr, int point, ObjRef value){
+    bool isNull = false;
+    if(value == NULL) isNull = true;
     if(0 > point || point >= getSize(arr)){
         printf("Index %i out of bounds for length %i\n",point, getSize(arr));
         exit(EXIT_FAILURE);
     }
+    if(arr == NULL) perror("Record is null");
     if(IS_PRIMITIVE(arr))  perror("Record is a primitive");
-    if(IS_PRIMITIVE(value)){
-        int size = value->size;
-        if((GET_REFS_PTR(arr)[point] = malloc(size)) == NULL) perror("malloc");
-        GET_REFS_PTR(arr)[point]->size = size;
-    }else{
-        int size = sizeof(*value) + (GET_ELEMENT_COUNT(value) * sizeof(void *));
-        if((GET_REFS_PTR(arr)[point] = malloc(size)) == NULL) perror("malloc");
-        GET_REFS_PTR(arr)[point] ->size = size;
+    int size;
+    if (isNull) size = sizeof(void *);
+    else {
+        if (IS_PRIMITIVE(value))
+            size = value->size;
+        else
+            size = sizeof(*value) + (GET_ELEMENT_COUNT(value) * sizeof(void *));
     }
+    if((GET_REFS_PTR(arr)[point] = malloc(size)) == NULL) perror("malloc");
+    GET_REFS_PTR(arr)[point] ->size = size;
     * (ObjRef *)GET_REFS_PTR(arr)[point]->data = value;
 }
 
diff --git a/stack.c b/stack.c
index 6925d71..34a9b91 100755
--- a/stack.c
+++ b/stack.c
@@ -8,9 +8,6 @@
 #include <stdlib.h>
 #include "stackslot.c"
 
-
-
-
 struct stack {
     int* size;
     int* current;
@@ -26,11 +23,13 @@ void printStack(struct stack stack, int fp) {
     printf("Stack\nSize:\t\t%i\nCurrent:\t%i\n", *stack.size, *stack.current);
     for (int i = *stack.current -1; i >= 0; --i) {
         printf("%i\t",i);
+        if(stack.stack[i].u.objRef == NULL) printf("|NULL|");
+        else
         if(stack.stack[i].isObjRef){
           printf("|%p|", (void *)stack.stack[i].u.objRef);
           if(stack.stack[i].u.objRef->size == sizeof(int))
             printf("(%i)",*(int *)stack.stack[i].u.objRef->data);
-        }else { 
+        }else {
         printf("|%i|", getIntValfromStackSlot(stack.stack[i]));
       }
       if(fp == i) printf("<-\tFP\n");
diff --git a/stackslot.c b/stackslot.c
index 6e28921..659a5eb 100644
--- a/stackslot.c
+++ b/stackslot.c
@@ -30,6 +30,7 @@ ObjRef getIntObj(int val) {
 }
 
 int getValFromIntObj(ObjRef iref) {
+    if (iref == NULL) perror("ObjRef is null");
     return *(int *) iref->data;
 }
 
@@ -41,6 +42,7 @@ int getIntValfromStackSlot(StackSlot s) {
 }
 
 void setValIntObj(ObjRef iref, int val) {
+    if (iref == NULL) perror("ObjRef is null");
     iref->size = sizeof(int)+sizeof(ObjRef);
     *(int *) iref->data = val;
 }