diff --git a/library/nist_kw.c b/library/nist_kw.c
index 9d7016e..d15c5c4 100644
--- a/library/nist_kw.c
+++ b/library/nist_kw.c
@@ -465,17 +465,22 @@
 
 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
 
-#define KW_TESTS 3
-
 /*
  * Test vectors taken from NIST
  * https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/CAVP-TESTING-BLOCK-CIPHER-MODES#KW
  */
-static const unsigned int key_len[KW_TESTS] = { 16, 24, 32 };
+static const unsigned int key_len[] = {
+    16,
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
+    24,
+    32
+#endif
+};
 
-static const unsigned char kw_key[KW_TESTS][32] = {
+static const unsigned char kw_key[][32] = {
     { 0x75, 0x75, 0xda, 0x3a, 0x93, 0x60, 0x7c, 0xc2,
       0xbf, 0xd8, 0xce, 0xc7, 0xaa, 0xdf, 0xd9, 0xa6 },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0x2d, 0x85, 0x26, 0x08, 0x1d, 0x02, 0xfb, 0x5b,
       0x85, 0xf6, 0x9a, 0xc2, 0x86, 0xec, 0xd5, 0x7d,
       0x40, 0xdf, 0x5d, 0xf3, 0x49, 0x47, 0x44, 0xd3 },
@@ -483,11 +488,13 @@
       0x4a, 0x98, 0x48, 0xd3, 0x0f, 0xdd, 0x78, 0x33,
       0x5b, 0x03, 0x9a, 0x48, 0xa8, 0x96, 0x2c, 0x4d,
       0x1c, 0xb7, 0x8e, 0xab, 0xd5, 0xda, 0xd7, 0x88 }
+#endif
 };
 
-static const unsigned char kw_msg[KW_TESTS][40] = {
+static const unsigned char kw_msg[][40] = {
     { 0x42, 0x13, 0x6d, 0x3c, 0x38, 0x4a, 0x3e, 0xea,
       0xc9, 0x5a, 0x06, 0x6f, 0xd2, 0x8f, 0xed, 0x3f },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0x95, 0xc1, 0x1b, 0xf5, 0x35, 0x3a, 0xfe, 0xdb,
       0x98, 0xfd, 0xd6, 0xc8, 0xca, 0x6f, 0xdb, 0x6d,
       0xa5, 0x4b, 0x74, 0xb4, 0x99, 0x0f, 0xdc, 0x45,
@@ -496,14 +503,28 @@
     { 0x1b, 0x20, 0xbf, 0x19, 0x90, 0xb0, 0x65, 0xd7,
       0x98, 0xe1, 0xb3, 0x22, 0x64, 0xad, 0x50, 0xa8,
       0x74, 0x74, 0x92, 0xba, 0x09, 0xa0, 0x4d, 0xd1 }
+#endif
 };
 
-static const size_t kw_msg_len[KW_TESTS] = { 16, 40, 24 };
-static const size_t kw_out_len[KW_TESTS] = { 24, 48, 32 };
-static const unsigned char kw_res[KW_TESTS][48] = {
+static const size_t kw_msg_len[] = {
+    16,
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
+    40,
+    24
+#endif
+};
+static const size_t kw_out_len[] = {
+    24,
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
+    48,
+    32
+#endif
+};
+static const unsigned char kw_res[][48] = {
     { 0x03, 0x1f, 0x6b, 0xd7, 0xe6, 0x1e, 0x64, 0x3d,
       0xf6, 0x85, 0x94, 0x81, 0x6f, 0x64, 0xca, 0xa3,
       0xf5, 0x6f, 0xab, 0xea, 0x25, 0x48, 0xf5, 0xfb },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0x44, 0x3c, 0x6f, 0x15, 0x09, 0x83, 0x71, 0x91,
       0x3e, 0x5c, 0x81, 0x4c, 0xa1, 0xa0, 0x42, 0xec,
       0x68, 0x2f, 0x7b, 0x13, 0x6d, 0x24, 0x3a, 0x4d,
@@ -514,11 +535,13 @@
       0xd5, 0xd5, 0x40, 0xec, 0x25, 0xd4, 0x3d, 0x87,
       0x20, 0x0f, 0xda, 0xdc, 0x6d, 0x1f, 0x05, 0xd9,
       0x16, 0x58, 0x4f, 0xa9, 0xf6, 0xcb, 0xf5, 0x12 }
+#endif
 };
 
-static const unsigned char kwp_key[KW_TESTS][32] = {
+static const unsigned char kwp_key[][32] = {
     { 0x78, 0x65, 0xe2, 0x0f, 0x3c, 0x21, 0x65, 0x9a,
       0xb4, 0x69, 0x0b, 0x62, 0x9c, 0xdf, 0x3c, 0xc4 },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0xf5, 0xf8, 0x96, 0xa3, 0xbd, 0x2f, 0x4a, 0x98,
       0x23, 0xef, 0x16, 0x2b, 0x00, 0xb8, 0x05, 0xd7,
       0xde, 0x1e, 0xa4, 0x66, 0x26, 0x96, 0xa2, 0x58 },
@@ -526,23 +549,33 @@
       0x25, 0x54, 0xee, 0x2a, 0x8d, 0xf1, 0x38, 0x6f,
       0x5b, 0x94, 0xa1, 0xa6, 0x0e, 0xd8, 0xa4, 0xae,
       0xf6, 0x0a, 0x8d, 0x61, 0xab, 0x5f, 0x22, 0x5a }
+#endif
 };
 
-static const unsigned char kwp_msg[KW_TESTS][31] = {
+static const unsigned char kwp_msg[][31] = {
     { 0xbd, 0x68, 0x43, 0xd4, 0x20, 0x37, 0x8d, 0xc8,
       0x96 },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0x6c, 0xcd, 0xd5, 0x85, 0x18, 0x40, 0x97, 0xeb,
       0xd5, 0xc3, 0xaf, 0x3e, 0x47, 0xd0, 0x2c, 0x19,
       0x14, 0x7b, 0x4d, 0x99, 0x5f, 0x96, 0x43, 0x66,
       0x91, 0x56, 0x75, 0x8c, 0x13, 0x16, 0x8f },
     { 0xd1 }
+#endif
 };
-static const size_t kwp_msg_len[KW_TESTS] = { 9, 31, 1 };
+static const size_t kwp_msg_len[] = {
+    9,
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
+    31,
+    1
+#endif
+};
 
-static const unsigned char kwp_res[KW_TESTS][48] = {
+static const unsigned char kwp_res[][48] = {
     { 0x41, 0xec, 0xa9, 0x56, 0xd4, 0xaa, 0x04, 0x7e,
       0xb5, 0xcf, 0x4e, 0xfe, 0x65, 0x96, 0x61, 0xe7,
       0x4d, 0xb6, 0xf8, 0xc5, 0x64, 0xe2, 0x35, 0x00 },
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
     { 0x4e, 0x9b, 0xc2, 0xbc, 0xbc, 0x6c, 0x1e, 0x13,
       0xd3, 0x35, 0xbc, 0xc0, 0xf7, 0x73, 0x6a, 0x88,
       0xfa, 0x87, 0x53, 0x66, 0x15, 0xbb, 0x8e, 0x63,
@@ -550,8 +583,15 @@
       0x67, 0xcf, 0xa9, 0x8a, 0x9d, 0x0e, 0x33, 0x26 },
     { 0x06, 0xba, 0x7a, 0xe6, 0xf3, 0x24, 0x8c, 0xfd,
       0xcf, 0x26, 0x75, 0x07, 0xfa, 0x00, 0x1b, 0xc4  }
+#endif
 };
-static const size_t kwp_out_len[KW_TESTS] = { 24, 40, 16 };
+static const size_t kwp_out_len[] = {
+    24,
+#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
+    40,
+    16
+#endif
+};
 
 int mbedtls_nist_kw_self_test(int verbose)
 {
@@ -562,127 +602,128 @@
     int ret = 0;
     mbedtls_nist_kw_init(&ctx);
 
-    for (i = 0; i < KW_TESTS; i++) {
-        if (verbose != 0) {
-            mbedtls_printf("  KW-AES-%u ", (unsigned int) key_len[i] * 8);
-        }
+    /*
+     * KW mode
+     */
+    {
+        static const int num_tests = sizeof(kw_key) / sizeof(*kw_key);
 
-#if defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
-        if (key_len[i] > 16) {
-            mbedtls_printf("skipped\n");
-            continue;
-        }
-#endif /* MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH */
-
-        ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
-                                     kw_key[i], key_len[i] * 8, 1);
-        if (ret != 0) {
+        for (i = 0; i < num_tests; i++) {
             if (verbose != 0) {
-                mbedtls_printf("  KW: setup failed ");
+                mbedtls_printf("  KW-AES-%u ", (unsigned int) key_len[i] * 8);
             }
 
-            goto end;
-        }
+            ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
+                                         kw_key[i], key_len[i] * 8, 1);
+            if (ret != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("  KW: setup failed ");
+                }
 
-        ret = mbedtls_nist_kw_wrap(&ctx, MBEDTLS_KW_MODE_KW, kw_msg[i],
-                                   kw_msg_len[i], out, &olen, sizeof(out));
-        if (ret != 0 || kw_out_len[i] != olen ||
-            memcmp(out, kw_res[i], kw_out_len[i]) != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("failed. ");
+                goto end;
             }
 
-            ret = 1;
-            goto end;
-        }
+            ret = mbedtls_nist_kw_wrap(&ctx, MBEDTLS_KW_MODE_KW, kw_msg[i],
+                                       kw_msg_len[i], out, &olen, sizeof(out));
+            if (ret != 0 || kw_out_len[i] != olen ||
+                memcmp(out, kw_res[i], kw_out_len[i]) != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("failed. ");
+                }
 
-        if ((ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
-                                          kw_key[i], key_len[i] * 8, 0))
-            != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("  KW: setup failed ");
+                ret = 1;
+                goto end;
             }
 
-            goto end;
-        }
+            if ((ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
+                                              kw_key[i], key_len[i] * 8, 0))
+                != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("  KW: setup failed ");
+                }
 
-        ret = mbedtls_nist_kw_unwrap(&ctx, MBEDTLS_KW_MODE_KW,
-                                     out, olen, out, &olen, sizeof(out));
-
-        if (ret != 0 || olen != kw_msg_len[i] ||
-            memcmp(out, kw_msg[i], kw_msg_len[i]) != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("failed\n");
+                goto end;
             }
 
-            ret = 1;
-            goto end;
-        }
+            ret = mbedtls_nist_kw_unwrap(&ctx, MBEDTLS_KW_MODE_KW,
+                                         out, olen, out, &olen, sizeof(out));
 
-        if (verbose != 0) {
-            mbedtls_printf(" passed\n");
+            if (ret != 0 || olen != kw_msg_len[i] ||
+                memcmp(out, kw_msg[i], kw_msg_len[i]) != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("failed\n");
+                }
+
+                ret = 1;
+                goto end;
+            }
+
+            if (verbose != 0) {
+                mbedtls_printf(" passed\n");
+            }
         }
     }
 
-    for (i = 0; i < KW_TESTS; i++) {
-        olen = sizeof(out);
-        if (verbose != 0) {
-            mbedtls_printf("  KWP-AES-%u ", (unsigned int) key_len[i] * 8);
-        }
-#if defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
-        if (key_len[i] > 16) {
-            mbedtls_printf("skipped\n");
-            continue;
-        }
-#endif /* MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH */
+    /*
+     * KWP mode
+     */
+    {
+        static const int num_tests = sizeof(kwp_key) / sizeof(*kwp_key);
 
-        ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, kwp_key[i],
-                                     key_len[i] * 8, 1);
-        if (ret  != 0) {
+        for (i = 0; i < num_tests; i++) {
+            olen = sizeof(out);
             if (verbose != 0) {
-                mbedtls_printf("  KWP: setup failed ");
+                mbedtls_printf("  KWP-AES-%u ", (unsigned int) key_len[i] * 8);
             }
 
-            goto end;
-        }
-        ret = mbedtls_nist_kw_wrap(&ctx, MBEDTLS_KW_MODE_KWP, kwp_msg[i],
-                                   kwp_msg_len[i], out, &olen, sizeof(out));
+            ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, kwp_key[i],
+                                         key_len[i] * 8, 1);
+            if (ret  != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("  KWP: setup failed ");
+                }
 
-        if (ret != 0 || kwp_out_len[i] != olen ||
-            memcmp(out, kwp_res[i], kwp_out_len[i]) != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("failed. ");
+                goto end;
+            }
+            ret = mbedtls_nist_kw_wrap(&ctx, MBEDTLS_KW_MODE_KWP, kwp_msg[i],
+                                       kwp_msg_len[i], out, &olen, sizeof(out));
+
+            if (ret != 0 || kwp_out_len[i] != olen ||
+                memcmp(out, kwp_res[i], kwp_out_len[i]) != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("failed. ");
+                }
+
+                ret = 1;
+                goto end;
             }
 
-            ret = 1;
-            goto end;
-        }
+            if ((ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
+                                              kwp_key[i], key_len[i] * 8, 0))
+                != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("  KWP: setup failed ");
+                }
 
-        if ((ret = mbedtls_nist_kw_setkey(&ctx, MBEDTLS_CIPHER_ID_AES,
-                                          kwp_key[i], key_len[i] * 8, 0))
-            != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("  KWP: setup failed ");
+                goto end;
             }
 
-            goto end;
-        }
+            ret = mbedtls_nist_kw_unwrap(&ctx, MBEDTLS_KW_MODE_KWP, out,
+                                         olen, out, &olen, sizeof(out));
 
-        ret = mbedtls_nist_kw_unwrap(&ctx, MBEDTLS_KW_MODE_KWP, out,
-                                     olen, out, &olen, sizeof(out));
+            if (ret != 0 || olen != kwp_msg_len[i] ||
+                memcmp(out, kwp_msg[i], kwp_msg_len[i]) != 0) {
+                if (verbose != 0) {
+                    mbedtls_printf("failed. ");
+                }
 
-        if (ret != 0 || olen != kwp_msg_len[i] ||
-            memcmp(out, kwp_msg[i], kwp_msg_len[i]) != 0) {
-            if (verbose != 0) {
-                mbedtls_printf("failed. ");
+                ret = 1;
+                goto end;
             }
 
-            ret = 1;
-            goto end;
-        }
-
-        if (verbose != 0) {
-            mbedtls_printf(" passed\n");
+            if (verbose != 0) {
+                mbedtls_printf(" passed\n");
+            }
         }
     }
 end: