diff --git a/cmd/okp4d/debug_extensions.go b/cmd/okp4d/debug_extensions.go
new file mode 100644
index 00000000..d0e72a8b
--- /dev/null
+++ b/cmd/okp4d/debug_extensions.go
@@ -0,0 +1,61 @@
+package main
+
+import (
+	"bufio"
+	"encoding/base64"
+	"encoding/json"
+
+	"github.com/spf13/cobra"
+	"github.com/tendermint/tendermint/proto/tendermint/types"
+)
+
+func ExtendDebugCmd(getCmd func(name string) (*cobra.Command, error)) error {
+	debugCmd, err := getCmd("debug")
+	if err != nil {
+		return err
+	}
+
+	debugCmd.AddCommand(DecodeBlocksCmd())
+	return nil
+}
+
+func DecodeBlocksCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "decode-blocks",
+		Short: "Decode base64 protobuf encoded blocks in JSON.",
+		Long:  "Read base64 protobuf encoded blocks from stdin and write the corresponding JSON representation on stdout.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			scanner := bufio.NewScanner(cmd.InOrStdin())
+			for scanner.Scan() {
+				strB64 := scanner.Text()
+				if strB64[0] == '"' {
+					strB64 = strB64[1:]
+				}
+				if strB64[len(strB64)-1] == '"' {
+					strB64 = strB64[:len(strB64)-1]
+				}
+
+				bytes, err := base64.StdEncoding.DecodeString(strB64)
+				if err != nil {
+					cmd.PrintErrln("could not decode base64 block:", err.Error())
+					continue
+				}
+
+				block := new(types.Block)
+				if err := block.Unmarshal(bytes); err != nil {
+					cmd.PrintErrln("could not decode block:", err.Error())
+					continue
+				}
+
+				json, err := json.Marshal(block)
+				if err != nil {
+					cmd.PrintErrln("could not marshal block in JSON:", err.Error())
+					continue
+				}
+				cmd.Println(string(json))
+			}
+
+			return nil
+		},
+	}
+}