diff --git a/tools/lz/dpcomp.c b/tools/lz/dpcomp.c
index ec6bce2248..19d904ff66 100644
--- a/tools/lz/dpcomp.c
+++ b/tools/lz/dpcomp.c
@@ -58,7 +58,7 @@ void process_input(void) {
         unsigned char current_byte = data[plen - 1];
         for (unsigned prev = plen > MAX_COMMAND_COUNT ? plen - MAX_COMMAND_COUNT : 0; prev < plen; prev++) {
             consider(plen, (struct command) {
-                .command = 0,
+                .command = LZ_DATA,
                 .count = plen - prev,
                 .value = prev,
             });
@@ -68,7 +68,7 @@ void process_input(void) {
         do {
             count++;
             consider(plen, (struct command) {
-                .command = current_byte ? 1 : 3,
+                .command = current_byte ? LZ_REPEAT : LZ_ZERO,
                 .count = count,
                 .value = current_byte,
             });
@@ -79,7 +79,7 @@ void process_input(void) {
             do {
                 count++;
                 consider(plen, (struct command) {
-                    .command = 2,
+                    .command = LZ_ALTERNATE,
                     .count = count,
                     .value = (data[plen - count + 1] << 8) | (data[plen - count]),
                 });
@@ -90,7 +90,7 @@ void process_input(void) {
             unsigned k = min(MAX_COMMAND_COUNT, match_right(plen - 1, at));
             for (unsigned i = 2; i <= k; i++) {
                 consider(plen + i - 1, (struct command) {
-                    .command = 4,
+                    .command = LZ_COPY_NORMAL,
                     .count = i,
                     .value = encode_delta(plen - 1, at),
                 });
@@ -99,7 +99,7 @@ void process_input(void) {
             k = min(MAX_COMMAND_COUNT, match_left(plen - 1, at));
             for (unsigned i = 2; i <= k; i++) {
                 consider(plen + i - 1, (struct command) {
-                    .command = 6,
+                    .command = LZ_COPY_REVERSED,
                     .count = i,
                     .value = encode_delta(plen - 1, at),
                 });
@@ -108,7 +108,7 @@ void process_input(void) {
             k = min(MAX_COMMAND_COUNT, match_flipped(plen - 1, at));
             for (unsigned i = 2; i <= k; i++) {
                 consider(plen + i - 1, (struct command) {
-                    .command = 5,
+                    .command = LZ_COPY_FLIPPED,
                     .count = i,
                     .value = encode_delta(plen - 1, at),
                 });
diff --git a/tools/lz/output.c b/tools/lz/output.c
index 3cef7b6454..053a5dce64 100644
--- a/tools/lz/output.c
+++ b/tools/lz/output.c
@@ -49,29 +49,29 @@ void write_command_to_textfile (FILE * fp, struct command command, const unsigne
   int rv, pos;
   const char * kind;
   switch (command.command) {
-    case 0:
+    case LZ_DATA:
       if ((rv = fprintf(fp, "\tlzdata")) < 0) break;
       for (pos = 0; pos < command.count; pos ++) if ((rv = fprintf(fp, "%s$%02hhx", pos ? ", " : " ", input_stream[command.value + pos])) < 0) break;
       rv = putc('\n', fp);
       break;
-    case 1:
+    case LZ_REPEAT:
       if ((command.value < 0) || (command.value > 255)) error_exit(2, "invalid command in output stream");
       rv = fprintf(fp, "\tlzrepeat %u, $%02hhx\n", command.count, (unsigned char) command.value);
       break;
-    case 2:
+    case LZ_ALTERNATE:
       if (command.value < 0) error_exit(2, "invalid command in output stream");
       rv = fprintf(fp, "\tlzrepeat %u, $%02hhx, $%02hhx\n", command.count, (unsigned char) command.value, (unsigned char) (command.value >> 8));
       break;
-    case 3:
+    case LZ_ZERO:
       rv = fprintf(fp, "\tlzzero %u\n", command.count);
       break;
-    case 4:
+    case LZ_COPY_NORMAL:
       kind = "normal";
       goto copy;
-    case 5:
+    case LZ_COPY_FLIPPED:
       kind = "flipped";
       goto copy;
-    case 6:
+    case LZ_COPY_REVERSED:
       kind = "reversed";
     copy:
       if ((command.value < -LOOKBACK_LIMIT) || (command.value >= MAX_FILE_SIZE)) error_exit(2, "invalid command in output stream");
@@ -113,10 +113,12 @@ void write_command_to_file (FILE * fp, struct command command, const unsigned ch
     *(pos ++) = command.count;
   }
   switch (command.command) {
-    case 1: case 2:
+    case LZ_REPEAT:
+    case LZ_ALTERNATE:
       if ((command.value < 0) || (command.value >= (1 << (command.command << 3)))) error_exit(2, "invalid command in output stream");
       for (n = 0; n < command.command; n ++) *(pos ++) = command.value >> (n << 3);
-    case 0: case 3:
+    case LZ_DATA:
+    case LZ_ZERO:
       break;
     default:
       if ((command.value < -LOOKBACK_LIMIT) || (command.value >= MAX_FILE_SIZE)) error_exit(2, "invalid command in output stream");
diff --git a/tools/lz/proto.h b/tools/lz/proto.h
index 5b9ff10ca2..b31fdd45ba 100644
--- a/tools/lz/proto.h
+++ b/tools/lz/proto.h
@@ -8,6 +8,15 @@
 #define MAX_COMMAND_COUNT          512
 #define LOOKBACK_LIMIT             128 /* highest negative valid count for a copy command */
 
+#define LZ_DATA          0 /* Read literal data for n bytes.   */
+#define LZ_REPEAT        1 /* Write the same byte for n bytes. */
+#define LZ_ALTERNATE     2 /* Alternate two bytes for n bytes. */
+#define LZ_ZERO          3 /* Write 0 for n bytes.             */
+#define LZ_COPY_NORMAL   4 /* Repeat n bytes from the offset.  */
+#define LZ_COPY_FLIPPED  5 /* Repeat n bitflipped bytes.       */
+#define LZ_COPY_REVERSED 6 /* Repeat n bytes in reverse.       */
+#define LZ_LONG          7 /* Expand n to 9 bits               */
+
 #if __STDC_VERSION__ >= 201112L
 	// <noreturn.h> forces "noreturn void", which is silly and redundant; this is simpler
 	#define noreturn _Noreturn void
diff --git a/tools/lz/uncomp.c b/tools/lz/uncomp.c
index b22fc75f65..0e5b078ed6 100644
--- a/tools/lz/uncomp.c
+++ b/tools/lz/uncomp.c
@@ -9,10 +9,10 @@ struct command * get_commands_from_file (const unsigned char * data, unsigned sh
     if (!(remaining --)) goto error;
     current -> command = *rp >> 5;
     current -> count = *(rp ++) & 31;
-    if (current -> command == 7) {
+    if (current -> command == LZ_LONG) {
       current -> command = current -> count >> 2;
       current -> count = (current -> count & 3) << 8;
-      if (current -> command == 7) {
+      if (current -> command == LZ_LONG) {
         // long commands inside long commands are not allowed, but if the count is 0x300 here, it means that the original byte was 0xff
         if (current -> count == 0x300) break;
         goto error;
@@ -22,14 +22,15 @@ struct command * get_commands_from_file (const unsigned char * data, unsigned sh
     }
     current -> count ++;
     switch (current -> command) {
-      case 0:
+      case LZ_DATA:
         if (remaining <= current -> count) goto error;
         current -> value = rp - data;
         rp += current -> count;
         remaining -= current -> count;
-      case 3:
+      case LZ_ZERO:
         break;
-      case 1: case 2: {
+      case LZ_REPEAT:
+      case LZ_ALTERNATE: {
         unsigned char p;
         if (remaining <= current -> command) goto error;
         current -> value = 0;
@@ -62,22 +63,23 @@ unsigned char * get_uncompressed_data (const struct command * commands, const un
   unsigned short p;
   for (; commands < limit; commands ++) {
     switch (commands -> command) {
-      case 0:
+      case LZ_DATA:
         memcpy(current, compressed + commands -> value, commands -> count);
         current += commands -> count;
         break;
-      case 1: case 2:
+      case LZ_REPEAT:
+      case LZ_ALTERNATE:
         for (p = 0; p < commands -> count; p ++) *(current ++) = commands -> value >> ((p % commands -> command) << 3);
         break;
-      case 3:
+      case LZ_ZERO:
         memset(current, 0, commands -> count);
         current += commands -> count;
         break;
       default: {
         const unsigned char * ref = ((commands -> value < 0) ? current : result) + commands -> value;
         for (p = 0; p < commands -> count; p ++) {
-          current[p] = ref[(commands -> command == 6) ? -(int) p : p];
-          if (commands -> command == 5) current[p] = bit_flipping_table[current[p]];
+          current[p] = ref[(commands -> command == LZ_COPY_REVERSED) ? -(int) p : p];
+          if (commands -> command == LZ_COPY_FLIPPED) current[p] = bit_flipping_table[current[p]];
         }
         current += commands -> count;
       }