diff --git a/icu4c/source/i18n/formattedvalue.cpp b/icu4c/source/i18n/formattedvalue.cpp
index 05a40ae..1030661 100644
--- a/icu4c/source/i18n/formattedvalue.cpp
+++ b/icu4c/source/i18n/formattedvalue.cpp
@@ -209,6 +209,8 @@
     if (pLength != nullptr) {
         *pLength = readOnlyAlias.length();
     }
+    // Note: this line triggers -Wreturn-local-addr, but it is safe because toTempString is
+    // defined to return memory owned by the ufmtval argument.
     return readOnlyAlias.getBuffer();
 }
 
diff --git a/icu4c/source/i18n/number_skeletons.cpp b/icu4c/source/i18n/number_skeletons.cpp
index ba9eee6..de70c5c 100644
--- a/icu4c/source/i18n/number_skeletons.cpp
+++ b/icu4c/source/i18n/number_skeletons.cpp
@@ -1358,7 +1358,9 @@
             priority = UNUM_ROUNDING_PRIORITY_STRICT;
             offset++;
         } else {
-            U_ASSERT(offset < segment.length());
+            // Invalid digits option for fraction rounder
+            status = U_NUMBER_SKELETON_SYNTAX_ERROR;
+            return false;
         }
         if (offset < segment.length()) {
             // Invalid digits option for fraction rounder