diff --git a/icu4c/source/i18n/coll.cpp b/icu4c/source/i18n/coll.cpp
index 2ccbb919b0..168e54500b 100644
--- a/icu4c/source/i18n/coll.cpp
+++ b/icu4c/source/i18n/coll.cpp
@@ -47,6 +47,7 @@
 #include "unicode/resbund.h"
 #include "mutex.h"
 #include "unicode/normlzr.h"
+#include "cmemory.h"
 
 //-----------------------------------------------------------------------------
 const UVersionInfo Collator::fVersion = {1, 0, 0, 0};
diff --git a/icu4c/source/i18n/tblcoll.cpp b/icu4c/source/i18n/tblcoll.cpp
index 1323bc20bc..4f04859ff1 100644
--- a/icu4c/source/i18n/tblcoll.cpp
+++ b/icu4c/source/i18n/tblcoll.cpp
@@ -77,6 +77,8 @@
 
 #include "unicode/ustring.h"
 
+#include "cmemory.h"
+
 
 class RuleBasedCollatorStreamer
 {