diff --git a/kalk/src/interpreter.rs b/kalk/src/interpreter.rs
index 736a559..e7ab16e 100644
--- a/kalk/src/interpreter.rs
+++ b/kalk/src/interpreter.rs
@@ -350,9 +350,6 @@ pub(crate) fn eval_fn_call_expr(
             return Ok(sum);
         }
         "integrate" => {
-            // Make sure either 3 or 4 arguments were supplied.
-            if expressions.len() < 3 || expressions.len() > 4 {}
-
             return match expressions.len() {
                 3 => calculus::integrate_with_unknown_variable(
                     context,
diff --git a/kalk/src/lexer.rs b/kalk/src/lexer.rs
index 3acca6c..f31f7d5 100644
--- a/kalk/src/lexer.rs
+++ b/kalk/src/lexer.rs
@@ -200,12 +200,14 @@ impl<'a> Lexer<'a> {
                 };
 
                 // Don't include eg. 0x in the value
-                start += 2;
-                end += 1;
-                self.advance();
-                value.clear();
-                leading_zero = false;
-                continue;
+                if base != 10 {
+                    start += 2;
+                    end += 1;
+                    self.advance();
+                    value.clear();
+                    leading_zero = false;
+                    continue;
+                }
             }
 
             if !c.is_digit(base) && c != '.' && c != '_' && !c.is_whitespace()