diff --git a/icu4c/source/common/udatamem.c b/icu4c/source/common/udatamem.c
index d08d7e8f84..db23eb101e 100644
--- a/icu4c/source/common/udatamem.c
+++ b/icu4c/source/common/udatamem.c
@@ -61,8 +61,9 @@ UDataMemory_normalizeDataPointer(const void *p) {
     } else {
 #ifdef OS400
         /*
-        WARNING! WARNING! WARNING!
-        This is a hack. This is here because this platform can't properly put
+        TODO: Fix this once the compiler implements this feature. Keep in sync with genccode.c
+
+        This is here because this platform can't currently put
         const data into the read-only pages of an object or
         shared library (service program). Only strings are allowed in read-only
         pages, so we use char * strings to store the data.
@@ -71,7 +72,7 @@ UDataMemory_normalizeDataPointer(const void *p) {
         magic numbers we must skip the initial double.
         [grhoten 4/24/2003]
         */
-        return (const DataHeader *)*((const char **)((const double *)p+1));
+        return (const DataHeader *)*((const void **)p+1);
 #else
         return (const DataHeader *)((const double *)p+1);
 #endif
diff --git a/icu4c/source/tools/genccode/genccode.c b/icu4c/source/tools/genccode/genccode.c
index 06a265dc7e..3e272d0b39 100644
--- a/icu4c/source/tools/genccode/genccode.c
+++ b/icu4c/source/tools/genccode/genccode.c
@@ -182,8 +182,9 @@ writeCCode(const char *filename, const char *destdir) {
 
 #ifdef OS400
     /*
-    WARNING! WARNING! WARNING!
-    This is a hack. This is here because this platform can't properly put
+    TODO: Fix this once the compiler implements this feature. Keep in sync with udatamem.c
+
+    This is here because this platform can't currently put
     const data into the read-only pages of an object or
     shared library (service program). Only strings are allowed in read-only
     pages, so we use char * strings to store the data.