diff --git a/slpkg/main.py b/slpkg/main.py
index e35e3db5..f2fb7b06 100644
--- a/slpkg/main.py
+++ b/slpkg/main.py
@@ -45,7 +45,7 @@ class Argparse:
         # Check for correct flag
         for opt in self.args:
             if opt.startswith('--'):
-                if opt not in self.options and opt != '--help':
+                if opt not in self.options and opt not in ['--help', '--version']:
                     raise SystemExit(f"\nError: flag '{opt}' does not exist.\n")
 
         # Remove flags from args
@@ -74,6 +74,9 @@ class Argparse:
         self.usage.help(1)
 
     def upgrade(self):
+        if [f for f in self.flags if f not in self.options[:-2]]:
+            self.usage.help(1)
+
         if len(self.args) == 1:
             self.check.database()
 
@@ -99,7 +102,10 @@ class Argparse:
         self.usage.help(1)
 
     def build(self):
-        if len(self.args) >= 2 and '--reinstall' not in self.flags:
+        if [f for f in self.flags if f not in self.options[:-3]]:
+            self.usage.help(1)
+
+        if len(self.args) >= 2:
             packages = list(set(self.args[1:]))
 
             self.check.database()
@@ -112,6 +118,9 @@ class Argparse:
         self.usage.help(1)
 
     def install(self):
+        if [f for f in self.flags if f not in self.options[:-1]]:
+            self.usage.help(1)
+
         if len(self.args) >= 2:
             packages = list(set(self.args[1:]))
 
@@ -154,6 +163,9 @@ class Argparse:
         self.usage.help(1)
 
     def view(self):
+        if [f for f in self.flags if f not in self.options[5]]:
+            self.usage.help(1)
+
         if len(self.args) >= 2:
             packages = list(set(self.args[1:]))