diff --git a/openhands-tools/openhands/tools/terminal/definition.py b/openhands-tools/openhands/tools/terminal/definition.py
index 69df4d4e94..dadad3223b 100644
--- a/openhands-tools/openhands/tools/terminal/definition.py
+++ b/openhands-tools/openhands/tools/terminal/definition.py
@@ -5,7 +5,7 @@
 from collections.abc import Sequence
 from typing import TYPE_CHECKING, Literal
 
-from pydantic import Field
+from pydantic import Field, model_validator
 
 
 if TYPE_CHECKING:
@@ -113,6 +113,17 @@ class TerminalAction(Action):
         description="If True, reset the terminal by creating a new session. Use this only when the terminal becomes unresponsive. Note that all previously set environment variables and session state will be lost after reset. Cannot be used with is_input=True.",  # noqa
     )
 
+    @model_validator(mode="before")
+    @classmethod
+    def _remap_commands_alias(cls, values: object) -> object:
+        # Some models (e.g. google/gemma-4) emit "commands" (plural) instead of
+        # the correct "command" field name. Silently remap before validation so
+        # the error-handling path is never reached for this known mismatch.
+        if isinstance(values, dict) and "commands" in values and "command" not in values:
+            values = dict(values)
+            values["command"] = values.pop("commands")
+        return values
+
     @property
     def visualize(self) -> Text:
         """Return Rich Text representation with a shell-style prompt."""
diff --git a/tests/tools/terminal/test_terminal_tool.py b/tests/tools/terminal/test_terminal_tool.py
index a1a0ec7707..a8c84e12e0 100644
--- a/tests/tools/terminal/test_terminal_tool.py
+++ b/tests/tools/terminal/test_terminal_tool.py
@@ -105,3 +105,26 @@ def test_bash_tool_to_openai_tool():
         assert openai_tool["function"]["name"] == "terminal"
         assert "description" in openai_tool["function"]
         assert "parameters" in openai_tool["function"]
+
+
+# ---------------------------------------------------------------------------
+# Tests for "commands" (plural) → "command" alias (google/gemma-4 mismatch)
+# ---------------------------------------------------------------------------
+
+
+def test_terminal_action_commands_alias_remapped():
+    """'commands' (plural) is silently remapped to 'command' (google/gemma-4)."""
+    action = TerminalAction.model_validate({"commands": "git remote -v"})
+    assert action.command == "git remote -v"
+
+
+def test_terminal_action_command_canonical_unchanged():
+    """'command' (singular, canonical) continues to work normally."""
+    action = TerminalAction.model_validate({"command": "echo hi"})
+    assert action.command == "echo hi"
+
+
+def test_terminal_action_command_takes_precedence_over_commands():
+    """When both keys are present, 'command' wins and 'commands' is ignored."""
+    action = TerminalAction.model_validate({"command": "echo hi", "commands": "echo ignored"})
+    assert action.command == "echo hi"