diff --git a/core/commands/cid.go b/core/commands/cid.go
index 017a5d191..b2e8f131d 100644
--- a/core/commands/cid.go
+++ b/core/commands/cid.go
@@ -80,11 +80,16 @@ The optional format string is a printf style format string:
 
 		switch verStr {
 		case "":
-			// noop
+			if baseStr != "" {
+				opts.verConv = toCidV1
+			}
 		case "0":
 			if opts.newCodec != 0 && opts.newCodec != cid.DagProtobuf {
 				return fmt.Errorf("cannot convert to CIDv0 with any codec other than dag-pb")
 			}
+			if baseStr != "" && baseStr != "base58btc" {
+				return fmt.Errorf("cannot convert to CIDv0 with any multibase other than the implicit base58btc")
+			}
 			opts.verConv = toCidV0
 		case "1":
 			opts.verConv = toCidV1
diff --git a/core/commands/cid_test.go b/core/commands/cid_test.go
new file mode 100644
index 000000000..106296282
--- /dev/null
+++ b/core/commands/cid_test.go
@@ -0,0 +1,111 @@
+package commands
+
+import (
+	"testing"
+
+	cmds "github.com/ipfs/go-ipfs-cmds"
+	"github.com/multiformats/go-multibase"
+)
+
+func TestCidFmtCmd(t *testing.T) {
+	t.Parallel()
+
+	// Test 'error when -v 0 is present and a custom -b is passed'
+	t.Run("ipfs cid format <cid> -b z -v 0", func(t *testing.T) {
+		t.Parallel()
+
+		type testV0PresentAndCustomBaseCase struct {
+			MultibaseName  string
+			ExpectedErrMsg string
+		}
+
+		var testV0PresentAndCustomBaseCases []testV0PresentAndCustomBaseCase
+
+		for _, e := range multibase.EncodingToStr {
+			var testCase testV0PresentAndCustomBaseCase
+
+			if e == "base58btc" {
+				testCase.MultibaseName = e
+				testCase.ExpectedErrMsg = ""
+				testV0PresentAndCustomBaseCases = append(testV0PresentAndCustomBaseCases, testCase)
+				continue
+			}
+			testCase.MultibaseName = e
+			testCase.ExpectedErrMsg = "cannot convert to CIDv0 with any multibase other than the implicit base58btc"
+			testV0PresentAndCustomBaseCases = append(testV0PresentAndCustomBaseCases, testCase)
+		}
+
+		for _, e := range testV0PresentAndCustomBaseCases {
+
+			// Mock request
+			req := &cmds.Request{
+				Options: map[string]interface{}{
+					cidVerisonOptionName:   "0",
+					cidMultibaseOptionName: e.MultibaseName,
+					cidFormatOptionName:    "%s",
+				},
+			}
+
+			// Response emitter
+			resp := cmds.ResponseEmitter(nil)
+
+			// Call the CidFmtCmd function with the mock request and response
+			err := cidFmtCmd.Run(req, resp, nil)
+			if err == nil && e.MultibaseName == "base58btc" {
+				continue
+			}
+
+			errMsg := err.Error()
+			if errMsg != e.ExpectedErrMsg {
+				t.Errorf("Expected %s, got %s instead", e.ExpectedErrMsg, errMsg)
+			}
+		}
+	})
+
+	// Test 'upgrade CID to v1 when passing a custom -b and no -v is specified'
+	t.Run("ipfs cid format <cid-version-0> -b z", func(t *testing.T) {
+		t.Parallel()
+
+		type testImplicitVersionAndCustomMultibaseCase struct {
+			Ver           string
+			CidV1         string
+			CidV0         string
+			MultibaseName string
+		}
+
+		var testCases = []testImplicitVersionAndCustomMultibaseCase{
+			{
+				Ver:           "",
+				CidV1:         "zdj7WWwMSWGoyxYkkT7mHgYvr6tV8CYd77aYxxqSbg9HsiMcE",
+				CidV0:         "QmPr755CxWUwt39C2Yiw4UGKrv16uZhSgeZJmoHUUS9TSJ",
+				MultibaseName: "z",
+			},
+			{
+				Ver:           "",
+				CidV1:         "CAFYBEIDI7ZABPGG3S63QW3AJG2XAZNE4NJQPN777WLWYRAIDG3TE5QFN3A======",
+				CidV0:         "QmVQVyEijmLb2cBQrowNQsaPbnUnJhfDK1sYe3wepm6ySf",
+				MultibaseName: "base32padupper",
+			},
+		}
+		for _, e := range testCases {
+			// Mock request
+			req := &cmds.Request{
+				Options: map[string]interface{}{
+					cidVerisonOptionName:   e.Ver,
+					cidMultibaseOptionName: e.MultibaseName,
+					cidFormatOptionName:    "%s",
+				},
+			}
+
+			// Response emitter
+			resp := cmds.ResponseEmitter(nil)
+
+			// Call the CidFmtCmd function with the mock request and response
+			err := cidFmtCmd.Run(req, resp, nil)
+
+			if err != nil {
+				t.Error(err)
+			}
+		}
+	})
+}