diff --git a/icu4c/source/common/strprep.h b/icu4c/source/common/strprep.h
index 900e200e0af..a062e189d07 100644
--- a/icu4c/source/common/strprep.h
+++ b/icu4c/source/common/strprep.h
@@ -316,7 +316,7 @@ inline UBool StringPrep::getNormalization(){
 }
 
 inline void StringPrep::getUnicodeVersion(UVersionInfo& info){
-    for(int32_t i=0; i< (sizeof(info)/sizeof(info[0])); i++){
+    for(int32_t i=0; i< (int32_t)(sizeof(info)/sizeof(info[0])); i++){
         info[i] = unicodeVersion[i];
     }
 }