diff --git a/packages/core/src/systems/en-US.ts b/packages/core/src/systems/en-US.ts
index 8873514..babb9f2 100644
--- a/packages/core/src/systems/en-US.ts
+++ b/packages/core/src/systems/en-US.ts
@@ -11,6 +11,9 @@ const NEGATIVE = 'negative' as const;
 
 const NEGATIVE_SYMBOL = '-' as const;
 
+// replace with hyphen with option
+const TENS_ONES_SEPARATOR = ' ' as const;
+
 const POSITIVE_SYMBOL = '+' as const;
 
 const SHORT_MILLIA_DELIMITER = '^' as const;
@@ -190,7 +193,7 @@ const makeTensName = (tens: number, ones: number) => {
 		return TENS[tens];
 	}
 
-	return `${TENS[tens] as Exclude<TensName, 'zero' | 'ten'>} ${ONES[ones] as Exclude<OnesName, 'zero'>}` as const;
+	return `${TENS[tens] as Exclude<TensName, 'zero' | 'ten'>}${TENS_ONES_SEPARATOR}${ONES[ones] as Exclude<OnesName, 'zero'>}` as const;
 };
 
 /**
@@ -409,7 +412,10 @@ export const makeNegative = (s: string) => (
 );
 
 export const tokenize = (stringValue: string) => (
-	stringValue.split(' ').filter((maybeToken) => maybeToken.length > 0)
+	stringValue
+		.replace(new RegExp(`${TENS_ONES_SEPARATOR}`, 'g'), ' ')
+		.split(' ')
+		.filter((maybeToken) => maybeToken.length > 0)
 );
 
 const FINAL_TOKEN = '' as const;