diff --git a/icu4c/source/test/iotest/filetst.c b/icu4c/source/test/iotest/filetst.c
index fc32978319..1a98d899df 100644
--- a/icu4c/source/test/iotest/filetst.c
+++ b/icu4c/source/test/iotest/filetst.c
@@ -1387,6 +1387,38 @@ static void TestVargs(void) {
 }
 #endif
 
+static void TestUnicodeFormat(void)
+{
+	/* Make sure that invariant conversion doesn't happen on the _u formats. */
+    UChar myUString[256];
+	UFILE *myFile;
+	static const UChar TEST_STR[] = { 0x03BC, 0x0025, 0x0024, 0};
+	static const UChar EXPECTED_STR[] = { 0x03BC, 0x03BC, 0x0025, 0x0024, 0};
+	static const UChar PERCENT_S[] = { 0x03BC, 0x0025, 0x0053, 0};
+
+	u_memset(myUString, 0x2a, sizeof(myUString)/sizeof(*myUString));
+
+    myFile = u_fopen(STANDARD_TEST_FILE, "w", NULL, "UTF-8");
+    if (!myFile) {
+        log_err("Test file can't be opened\n");
+        return;
+    }
+	u_fprintf_u(myFile, PERCENT_S, TEST_STR);
+	u_fclose(myFile);
+
+    myFile = u_fopen(STANDARD_TEST_FILE, "r", NULL, "UTF-8");
+    if (!myFile) {
+        log_err("Test file can't be opened\n");
+        return;
+    }
+	u_fscanf_u(myFile, PERCENT_S, myUString);
+	u_fclose(myFile);
+	if (u_strcmp(TEST_STR, myUString) != 0) {
+        log_err("u_fscanf_u doesn't work.\n");
+	}
+}
+
+
 U_CFUNC void
 addFileTest(TestNode** root) {
 #if !UCONFIG_NO_FORMATTING
@@ -1408,4 +1440,5 @@ addFileTest(TestNode** root) {
     addTest(root, &TestBadScanfFormat, "file/TestBadScanfFormat");
     addTest(root, &TestVargs, "file/TestVargs");
 #endif
+    addTest(root, &TestUnicodeFormat, "file/TestUnicodeFormat");
 }
diff --git a/icu4c/source/test/testdata/icuio.txt b/icu4c/source/test/testdata/icuio.txt
index 3931d768b8..f33ce79e49 100644
--- a/icu4c/source/test/testdata/icuio.txt
+++ b/icu4c/source/test/testdata/icuio.txt
@@ -48,6 +48,12 @@ icuio {
                 { "%-5.3s", "abc  ", "s", "abcdef" }
                 { "%5.3s", "    a", "s", "a" }
                 { "%-5.3s", "a    ", "s", "a" }
+                { "%.3P", "120.000%", "d", "1.2" }
+                { "%.0P", "120%", "d", "1.2" }
+                { "%.3P", "1.200%", "d", "0.012" }
+                { "%.0P", "1%", "d", "0.012" }
+                { "%04.0P", "001%", "d", "0.012" }
+                { "%+4.0P", " +1%", "d", "0.012" }
                 { "%e", "1.200000e+000", "d", "1.2" }
                 { "%e", "1.234568e+006", "d", "1234567.89" }
                 { "%E", "1.234568E+006", "d", "1234567.89" }