diff --git a/src/bitops.c b/src/bitops.c
index 493811b56..a886e04db 100644
--- a/src/bitops.c
+++ b/src/bitops.c
@@ -1454,7 +1454,7 @@ void bitopCommand(client *c) {
     addReplyLongLong(c,maxlen); /* Return the output string length in bytes. */
 }
 
-/* BITCOUNT key [start end [BIT|BYTE]] */
+/* BITCOUNT key [start [end [BIT|BYTE]]] */
 void bitcountCommand(client *c) {
     kvobj *o;
     long long start, end;
@@ -1465,11 +1465,9 @@ void bitcountCommand(client *c) {
     unsigned char first_byte_neg_mask = 0, last_byte_neg_mask = 0;
 
     /* Parse start/end range if any. */
-    if (c->argc == 4 || c->argc == 5) {
+    if (c->argc == 3 || c->argc == 4 || c->argc == 5) {
         if (getLongLongFromObjectOrReply(c,c->argv[2],&start,NULL) != C_OK)
             return;
-        if (getLongLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
-            return;
         if (c->argc == 5) {
             if (!strcasecmp(c->argv[4]->ptr,"bit")) isbit = 1;
             else if (!strcasecmp(c->argv[4]->ptr,"byte")) isbit = 0;
@@ -1478,21 +1476,32 @@ void bitcountCommand(client *c) {
                 return;
             }
         }
+        if (c->argc >= 4) {
+            if (getLongLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
+                return;
+        }
+
         /* Lookup, check for type. */
         o = lookupKeyRead(c->db, c->argv[1]);
         if (checkType(c, o, OBJ_STRING)) return;
         p = getObjectReadOnlyString(o,&strlen,llbuf);
-        long long totlen = strlen;
 
         /* Make sure we will not overflow */
+        long long totlen = strlen;
         serverAssert(totlen <= LLONG_MAX >> 3);
 
+        if (c->argc < 4) {
+            if (isbit) end = (totlen<<3) + 7;
+            else end = totlen-1;
+        }
+
         /* Convert negative indexes */
         if (start < 0 && end < 0 && start > end) {
             addReply(c,shared.czero);
             return;
         }
         if (isbit) totlen <<= 3;
+        /* Convert negative indexes */
         if (start < 0) start = totlen+start;
         if (end < 0) end = totlen+end;
         if (start < 0) start = 0;
@@ -1511,6 +1520,7 @@ void bitcountCommand(client *c) {
         o = lookupKeyRead(c->db, c->argv[1]);
         if (checkType(c, o, OBJ_STRING)) return;
         p = getObjectReadOnlyString(o,&strlen,llbuf);
+
         /* The whole string. */
         start = 0;
         end = strlen-1;
diff --git a/src/commands.def b/src/commands.def
index af7201453..d3c3f9da6 100644
--- a/src/commands.def
+++ b/src/commands.def
@@ -51,23 +51,28 @@ keySpec BITCOUNT_Keyspecs[1] = {
 };
 #endif
 
-/* BITCOUNT range unit argument table */
-struct COMMAND_ARG BITCOUNT_range_unit_Subargs[] = {
+/* BITCOUNT range end_unit_block unit argument table */
+struct COMMAND_ARG BITCOUNT_range_end_unit_block_unit_Subargs[] = {
 {MAKE_ARG("byte",ARG_TYPE_PURE_TOKEN,-1,"BYTE",NULL,NULL,CMD_ARG_NONE,0,NULL)},
 {MAKE_ARG("bit",ARG_TYPE_PURE_TOKEN,-1,"BIT",NULL,NULL,CMD_ARG_NONE,0,NULL)},
 };
 
+/* BITCOUNT range end_unit_block argument table */
+struct COMMAND_ARG BITCOUNT_range_end_unit_block_Subargs[] = {
+{MAKE_ARG("end",ARG_TYPE_INTEGER,-1,NULL,NULL,NULL,CMD_ARG_NONE,0,NULL)},
+{MAKE_ARG("unit",ARG_TYPE_ONEOF,-1,NULL,NULL,"7.0.0",CMD_ARG_OPTIONAL,2,NULL),.subargs=BITCOUNT_range_end_unit_block_unit_Subargs},
+};
+
 /* BITCOUNT range argument table */
 struct COMMAND_ARG BITCOUNT_range_Subargs[] = {
 {MAKE_ARG("start",ARG_TYPE_INTEGER,-1,NULL,NULL,NULL,CMD_ARG_NONE,0,NULL)},
-{MAKE_ARG("end",ARG_TYPE_INTEGER,-1,NULL,NULL,NULL,CMD_ARG_NONE,0,NULL)},
-{MAKE_ARG("unit",ARG_TYPE_ONEOF,-1,NULL,NULL,"7.0.0",CMD_ARG_OPTIONAL,2,NULL),.subargs=BITCOUNT_range_unit_Subargs},
+{MAKE_ARG("end-unit-block",ARG_TYPE_BLOCK,-1,NULL,NULL,NULL,CMD_ARG_OPTIONAL,2,NULL),.subargs=BITCOUNT_range_end_unit_block_Subargs},
 };
 
 /* BITCOUNT argument table */
 struct COMMAND_ARG BITCOUNT_Args[] = {
 {MAKE_ARG("key",ARG_TYPE_KEY,0,NULL,NULL,NULL,CMD_ARG_NONE,0,NULL)},
-{MAKE_ARG("range",ARG_TYPE_BLOCK,-1,NULL,NULL,NULL,CMD_ARG_OPTIONAL,3,NULL),.subargs=BITCOUNT_range_Subargs},
+{MAKE_ARG("range",ARG_TYPE_BLOCK,-1,NULL,NULL,NULL,CMD_ARG_OPTIONAL,2,NULL),.subargs=BITCOUNT_range_Subargs},
 };
 
 /********** BITFIELD ********************/
diff --git a/src/commands/bitcount.json b/src/commands/bitcount.json
index 2d277a855..616e9fa02 100644
--- a/src/commands/bitcount.json
+++ b/src/commands/bitcount.json
@@ -54,24 +54,31 @@
                         "type": "integer"
                     },
                     {
-                        "name": "end",
-                        "type": "integer"
-                    },
-                    {
-                        "name": "unit",
-                        "type": "oneof",
+                        "name": "end-unit-block",
+                        "type": "block",
                         "optional": true,
-                        "since": "7.0.0",
                         "arguments": [
                             {
-                                "name": "byte",
-                                "type": "pure-token",
-                                "token": "BYTE"
+                                "name": "end",
+                                "type": "integer"
                             },
                             {
-                                "name": "bit",
-                                "type": "pure-token",
-                                "token": "BIT"
+                                "name": "unit",
+                                "type": "oneof",
+                                "optional": true,
+                                "since": "7.0.0",
+                                "arguments": [
+                                    {
+                                        "name": "byte",
+                                        "type": "pure-token",
+                                        "token": "BYTE"
+                                    },
+                                    {
+                                        "name": "bit",
+                                        "type": "pure-token",
+                                        "token": "BIT"
+                                    }
+                                ]
                             }
                         ]
                     }
diff --git a/tests/unit/bitops.tcl b/tests/unit/bitops.tcl
index 23b27362b..06c16ee07 100644
--- a/tests/unit/bitops.tcl
+++ b/tests/unit/bitops.tcl
@@ -147,6 +147,15 @@ start_server {tags {"bitops"}} {
         }
     }
 
+    test {BITCOUNT with start} {
+        set s "foobar"
+        r set s $s
+        assert_equal [r bitcount s 0] [count_bits "foobar"]
+        assert_equal [r bitcount s 1] [count_bits "oobar"]
+        assert_equal [r bitcount s -1] [count_bits "r"]
+        assert_equal [r bitcount s -2] [count_bits "ar"]
+    }
+
     test {BITCOUNT with start, end} {
         set s "foobar"
         r set s $s
@@ -169,12 +178,10 @@ start_server {tags {"bitops"}} {
     test {BITCOUNT with illegal arguments} {
         # Used to return 0 for non-existing key instead of errors
         r del s
-        assert_error {ERR *syntax*} {r bitcount s 0}
         assert_error {ERR *syntax*} {r bitcount s 0 1 hello}
         assert_error {ERR *syntax*} {r bitcount s 0 1 hello hello2}
 
         r set s 1
-        assert_error {ERR *syntax*} {r bitcount s 0}
         assert_error {ERR *syntax*} {r bitcount s 0 1 hello}
         assert_error {ERR *syntax*} {r bitcount s 0 1 hello hello2}
     }