diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 0b113308..1d6c38d3 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1171,6 +1171,12 @@ bool statusOk(int status)
 }
 
 
+bool hasPrefix(const string & s, const string & suffix)
+{
+    return s.compare(0, suffix.size(), suffix) == 0;
+}
+
+
 bool hasSuffix(const string & s, const string & suffix)
 {
     return s.size() >= suffix.size() && string(s, s.size() - suffix.size()) == suffix;
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index cf93c637..8abb1c8d 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -365,6 +365,10 @@ template<class N> bool string2Int(const string & s, N & n)
 }
 
 
+/* Return true iff `s' starts with `prefix'. */
+bool hasPrefix(const string & s, const string & prefix);
+
+
 /* Return true iff `s' ends in `suffix'. */
 bool hasSuffix(const string & s, const string & suffix);