diff --git a/src/grammar.y b/src/grammar.y
index 2751080..cfcc476 100644
--- a/src/grammar.y
+++ b/src/grammar.y
@@ -445,6 +445,7 @@ declaration:
             printdebug("ID/TYPE: %s,  ID: %s", getName((TableNode*)$1), $3) ;
             int d = getAdInfoType((TableNode*)$1);
             if(d == TYPE_UNDEFINED) {
+                throw_error(ERROR_TYPE, "Undefined type passed in declaration list");
                 printdebug("Undefined type passed in declaration list");
                 CreateEntry(cur,d,(TableNode*)$1,$3,getAdInfo((TableNode*)$1)); 
             }
@@ -468,7 +469,7 @@ declaration:
                 d = TYPE_PRIMITIVE;
                 CreateEntry(cur,d,(TableNode*)$1,$3,getAdInfo((TableNode*)$1)); 
             }else {
-                printdebug("Invalid type passed in declaration list.");
+                throw_error(ERROR_TYPE, "%s is being defined with an undefined type", $3);
                 CreateEntry(cur,d,(TableNode*)$1,$3,getAdInfo((TableNode*)$1)); 
             }
         }
@@ -841,6 +842,9 @@ assignable:
         ID 
         {
             TableNode* pass = look_up(cur,$1);
+            if(pass == undefined){
+                throw_error(ERROR_TYPE, "Undefined variable %s", $1);
+            }
             $$ = pass; 
             printdebug("[ASSIGNABLE - RULE 1] assignable = type: %s | ID = %s", getType(pass), getName(pass));
         }