diff --git a/tools/icu/iculslocs.cc b/tools/icu/iculslocs.cc
index 3ceb8d2a4d81d0..a6931d3a9a62d6 100644
--- a/tools/icu/iculslocs.cc
+++ b/tools/icu/iculslocs.cc
@@ -55,6 +55,7 @@ Japanese, it doesn't *claim* to have Japanese.
 #include <unicode/ures.h>
 #include <unicode/udata.h>
 #include <unicode/putil.h>
+#include <stdio.h>
 
 const char* PROG = "iculslocs";
 const char* NAME = U_ICUDATA_NAME;  // assume ICU data