diff --git a/src/strings_func.h b/src/strings_func.h
--- a/src/strings_func.h
+++ b/src/strings_func.h
@@ -122,8 +122,6 @@ public:
 		return (int32)this->GetInt64(type);
 	}
 
-	void ShiftParameters(uint amount);
-
 	/** Get a pointer to the current element in the data array. */
 	uint64 *GetDataPointer() const
 	{
@@ -179,8 +177,6 @@ const char *GetStringPtr(StringID string
 uint ConvertKmhishSpeedToDisplaySpeed(uint speed);
 uint ConvertDisplaySpeedToKmhishSpeed(uint speed);
 
-void InjectDParam(uint amount);
-
 /**
  * Set a string parameter \a v at index \a n in a given array \a s.
  * @param s Array of string parameters.