diff --git a/src/rpn.rs b/src/rpn.rs
index 737325c..83af537 100644
--- a/src/rpn.rs
+++ b/src/rpn.rs
@@ -78,6 +78,10 @@ impl fmt::Display for EvaluationError {
 	}
 }
 
+// I’m no math nerd but I want the highest possible approximation of 0.9
+// repeating and it seems this can give it to me
+const PRECISION_MOD: f64 = 0.9 + f64::EPSILON * 100.0;
+
 // str_to_calc_type converts a string to an optional `CalcType`.
 fn str_to_calc_type(string: &str) -> Option<CalcType> {
 	let as_int = string.parse::<f64>();
@@ -186,7 +190,7 @@ fn main() -> ExitCode {
 	let argv = args().collect::<Vec<String>>();
 	let mut stack = VecDeque::new();
 	let mut buf = String::new();
-	let precision = (-f64::EPSILON.log10() * 0.999).ceil() as usize;
+	let precision = (-f64::EPSILON.log10() * PRECISION_MOD).ceil() as usize;
 	
 	if argv.get(1).is_none() {
 		while let Ok(_) = stdin().read_line(&mut buf) {