diff --git a/icu4c/source/test/intltest/dadrfmt.cpp b/icu4c/source/test/intltest/dadrfmt.cpp
index fe901054e76..1c8ac600892 100644
--- a/icu4c/source/test/intltest/dadrfmt.cpp
+++ b/icu4c/source/test/intltest/dadrfmt.cpp
@@ -221,7 +221,8 @@ void DataDrivenFormatTest::testConvertDate(TestData *testData,
             if(output == expectStr) {
                 logln(caseString+": format: SUCCESS! "+UnicodeString("expect=output=")+output);
             } else {
-                errln(caseString+": format:  output!=expectStr, got " + udbg_escape(output) + " expected " + udbg_escape(expectStr));
+                UnicodeString result;
+                errln(caseString+": format:  output!=expectStr, got " + *udbg_escape(output, &result) + " expected " + *udbg_escape(expectStr, &result));
             }
         } else {
             cal->clear();
diff --git a/icu4c/source/tools/ctestfw/dbgutil.cpp b/icu4c/source/tools/ctestfw/dbgutil.cpp
index f1b9867a15d..7419138cd55 100644
--- a/icu4c/source/tools/ctestfw/dbgutil.cpp
+++ b/icu4c/source/tools/ctestfw/dbgutil.cpp
@@ -11,6 +11,7 @@
 
 #include "unicode/unistr.h"
 #include "unicode/ustring.h"
+#include "util.h"
 #include "ucln.h"
 
 #include <stdio.h>
@@ -117,22 +118,19 @@ udbg_stoi(const UnicodeString &s)
     return atoi(ch);
 }
 
-// from incaltst.cpp
-T_CTEST_API UnicodeString
-udbg_escape(const UnicodeString &src)
+T_CTEST_API UnicodeString *
+udbg_escape(const UnicodeString &src, UnicodeString *dst)
 {
-  UnicodeString dst;
-    dst.remove();
+    dst->remove();
     for (int32_t i = 0; i < src.length(); ++i) {
         UChar c = src[i];
-        if(c < 0x0080)
-            dst += c;
+        if(ICU_Utility::isUnprintable(c)) {
+            *dst += UnicodeString("[");
+            ICU_Utility::escapeUnprintable(*dst, c);
+            *dst += UnicodeString("]");
+        }
         else {
-            dst += UnicodeString("[");
-            char buf [8];
-            sprintf(buf, "%#x", c);
-            dst += UnicodeString(buf);
-            dst += UnicodeString("]");
+            *dst += c;
         }
     }
 
diff --git a/icu4c/source/tools/ctestfw/unicode/dbgutil.h b/icu4c/source/tools/ctestfw/unicode/dbgutil.h
index d8ae43a216e..e4d9cc7f1a8 100644
--- a/icu4c/source/tools/ctestfw/unicode/dbgutil.h
+++ b/icu4c/source/tools/ctestfw/unicode/dbgutil.h
@@ -31,7 +31,7 @@ T_CTEST_API int32_t  T_CTEST_EXPORT2 udbg_enumByString(UDebugEnumType type, cons
  */
 T_CTEST_API int32_t T_CTEST_EXPORT2 udbg_stoi(const UnicodeString &s);
 
-T_CTEST_API UnicodeString udbg_escape(const UnicodeString &s);
+T_CTEST_API UnicodeString *udbg_escape(const UnicodeString &s, UnicodeString *dst);
 
 #endif