diff --git a/dlls/msvcrt/printf.h b/dlls/msvcrt/printf.h
index f68eaf66cd1..ce7a70e7571 100644
--- a/dlls/msvcrt/printf.h
+++ b/dlls/msvcrt/printf.h
@@ -473,6 +473,10 @@ int FUNC_NAME(pf_printf)(FUNC_NAME(puts_clbk) pf_puts, void *puts_ctx, const API
                     flags.IntegerNative = *p++;
             } else if(*p == 'w')
                 flags.WideString = *p++;
+#if _MSVCR_VER >= 140
+            else if(*p == 'z')
+                flags.IntegerNative = *p++;
+#endif
             else if((*p == 'F' || *p == 'N') && legacy_msvcrt_compat)
                 p++; /* ignore */
             else
diff --git a/dlls/msvcrt/tests/printf.c b/dlls/msvcrt/tests/printf.c
index c8797f3bda8..295c6dd3020 100644
--- a/dlls/msvcrt/tests/printf.c
+++ b/dlls/msvcrt/tests/printf.c
@@ -321,6 +321,11 @@ static void test_sprintf( void )
     ok(!strcmp(buffer,"D"),"I64D failed: %s\n",buffer);
     ok( r==1, "return count wrong\n");
 
+    format = "%zx";
+    r = sprintf(buffer,format,1);
+    ok(!strcmp(buffer, "zx"), "Problem with \"z\" interpretation\n");
+    ok( r==2, "return count wrong\n");
+
     format = "% d";
     r = sprintf(buffer,format,1);
     ok(!strcmp(buffer, " 1"),"Problem with sign place-holder: '%s'\n",buffer);
diff --git a/dlls/ucrtbase/tests/printf.c b/dlls/ucrtbase/tests/printf.c
index ae12b60d385..6c719eaf4b4 100644
--- a/dlls/ucrtbase/tests/printf.c
+++ b/dlls/ucrtbase/tests/printf.c
@@ -423,6 +423,29 @@ static void test_printf_legacy_three_digit_exp(void)
     ok(!strcmp(buf, "1.230000E+123"), "buf = %s\n", buf);
 }
 
+static void test_printf_c99(void)
+{
+    char buf[20];
+
+    /* The msvcrt compatibility flag doesn't affect whether 'z' is interpreted
+     * as size_t size for integers. */
+    if (sizeof(void*) == 8) {
+        vsprintf_wrapper(0, buf, sizeof(buf), "%zx %d",
+                         (size_t) 0x12345678123456, 1);
+        ok(!strcmp(buf, "12345678123456 1"), "buf = %s\n", buf);
+        vsprintf_wrapper(UCRTBASE_PRINTF_LEGACY_MSVCRT_COMPATIBILITY,
+                         buf, sizeof(buf), "%zx %d", (size_t) 0x12345678123456, 1);
+        ok(!strcmp(buf, "12345678123456 1"), "buf = %s\n", buf);
+    } else {
+        vsprintf_wrapper(0, buf, sizeof(buf), "%zx %d",
+                         (size_t) 0x123456, 1);
+        ok(!strcmp(buf, "123456 1"), "buf = %s\n", buf);
+        vsprintf_wrapper(UCRTBASE_PRINTF_LEGACY_MSVCRT_COMPATIBILITY,
+                         buf, sizeof(buf), "%zx %d", (size_t) 0x123456, 1);
+        ok(!strcmp(buf, "123456 1"), "buf = %s\n", buf);
+    }
+}
+
 START_TEST(printf)
 {
     if (!init()) return;
@@ -434,4 +457,5 @@ START_TEST(printf)
     test_printf_legacy_wide();
     test_printf_legacy_msvcrt();
     test_printf_legacy_three_digit_exp();
+    test_printf_c99();
 }