diff --git a/icu4c/source/test/depstest/dependencies.txt b/icu4c/source/test/depstest/dependencies.txt
index 58c35d7764dd..1486b779f767 100644
--- a/icu4c/source/test/depstest/dependencies.txt
+++ b/icu4c/source/test/depstest/dependencies.txt
@@ -145,6 +145,7 @@ group: iostream
     "std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)"
     std::ios_base::Init::Init()
     std::ios_base::Init::~Init()
+    std::ios_base_library_init()
     std::istream::get()
     std::istream::putback(char)
     # Additional symbols in an optimized build.
diff --git a/icu4c/source/test/fuzzer/locale_util.h b/icu4c/source/test/fuzzer/locale_util.h
index 09848ff4a37b..85594454f87e 100644
--- a/icu4c/source/test/fuzzer/locale_util.h
+++ b/icu4c/source/test/fuzzer/locale_util.h
@@ -4,6 +4,7 @@
 #ifndef I18N_ICU_FUZZ_LOCALE_UTIL_H_
 #define I18N_ICU_FUZZ_LOCALE_UTIL_H_
 
+#include <cstdint>
 #include <string>
 
 // Takes uint8_t data from fuzzer, and makes a zero terminated string.