diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 16affdd..4dd64f8 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -1891,7 +1891,7 @@
 "S.find(sub [,start [,end]]) -> int\n\
 \n\
 Return the lowest index in S where substring sub is found,\n\
-such that sub is contained within s[start,end].  Optional\n\
+such that sub is contained within s[start:end].  Optional\n\
 arguments start and end are interpreted as in slice notation.\n\
 \n\
 Return -1 on failure.");
@@ -1930,7 +1930,7 @@
 "S.rfind(sub [,start [,end]]) -> int\n\
 \n\
 Return the highest index in S where substring sub is found,\n\
-such that sub is contained within s[start,end].  Optional\n\
+such that sub is contained within s[start:end].  Optional\n\
 arguments start and end are interpreted as in slice notation.\n\
 \n\
 Return -1 on failure.");