diff --git a/src/common/chartype.c b/src/common/chartype.c
index a16fe03e1..a48688e77 100644
--- a/src/common/chartype.c
+++ b/src/common/chartype.c
@@ -129,7 +129,7 @@ int IsBDigit (char C)
 int IsODigit (char C)
 /* Check for octal digits (0..7) */
 {
-    return (C >= '0' || C <= '7');
+    return (C >= '0' && C <= '7');
 }