diff --git a/changelog.d/6844.bugfix b/changelog.d/6844.bugfix
new file mode 100644
index 0000000000..a2babaaa6d
--- /dev/null
+++ b/changelog.d/6844.bugfix
@@ -0,0 +1 @@
+Fixes /addToSpace and /joinSpace commands showing invalid syntax warnings
diff --git a/vector/src/main/java/im/vector/app/features/command/CommandParser.kt b/vector/src/main/java/im/vector/app/features/command/CommandParser.kt
index 1378321026..be3cabfc18 100644
--- a/vector/src/main/java/im/vector/app/features/command/CommandParser.kt
+++ b/vector/src/main/java/im/vector/app/features/command/CommandParser.kt
@@ -374,15 +374,15 @@ class CommandParser @Inject constructor() {
                     }
                 }
                 Command.ADD_TO_SPACE.matches(slashCommand) -> {
-                    if (messageParts.size == 1) {
-                        ParsedCommand.AddToSpace(spaceId = message)
+                    if (messageParts.size == 2) {
+                        ParsedCommand.AddToSpace(spaceId = messageParts.last())
                     } else {
                         ParsedCommand.ErrorSyntax(Command.ADD_TO_SPACE)
                     }
                 }
                 Command.JOIN_SPACE.matches(slashCommand) -> {
-                    if (messageParts.size == 1) {
-                        ParsedCommand.JoinSpace(spaceIdOrAlias = message)
+                    if (messageParts.size == 2) {
+                        ParsedCommand.JoinSpace(spaceIdOrAlias = messageParts.last())
                     } else {
                         ParsedCommand.ErrorSyntax(Command.JOIN_SPACE)
                     }
diff --git a/vector/src/test/java/im/vector/app/features/command/CommandParserTest.kt b/vector/src/test/java/im/vector/app/features/command/CommandParserTest.kt
index f5233a496c..c257377849 100644
--- a/vector/src/test/java/im/vector/app/features/command/CommandParserTest.kt
+++ b/vector/src/test/java/im/vector/app/features/command/CommandParserTest.kt
@@ -19,6 +19,8 @@ package im.vector.app.features.command
 import org.amshove.kluent.shouldBeEqualTo
 import org.junit.Test
 
+private const val A_SPACE_ID = "!my-space-id"
+
 class CommandParserTest {
     @Test
     fun parseSlashCommandEmpty() {
@@ -31,6 +33,15 @@ class CommandParserTest {
         test("/unknown with param", ParsedCommand.ErrorUnknownSlashCommand("/unknown"))
     }
 
+    @Test
+    fun parseSlashAddToSpaceCommand() {
+        test("/addToSpace $A_SPACE_ID", ParsedCommand.AddToSpace(A_SPACE_ID))
+    }
+    @Test
+    fun parseSlashJoinSpaceCommand() {
+        test("/joinSpace $A_SPACE_ID", ParsedCommand.JoinSpace(A_SPACE_ID))
+    }
+
     @Test
     fun parseSlashCommandNotACommand() {
         test("", ParsedCommand.ErrorNotACommand)