diff --git a/src/modules/systemlib/flashparams/flashparams.c b/src/modules/systemlib/flashparams/flashparams.c
index 92db1cc2f5..6f32bb2731 100644
--- a/src/modules/systemlib/flashparams/flashparams.c
+++ b/src/modules/systemlib/flashparams/flashparams.c
@@ -65,8 +65,8 @@
  * Storage for modified parameters.
  */
 struct param_wbuf_s {
-	param_t                 param;
 	union param_value_u     val;
+	param_t                 param;
 	bool                    unsaved;
 };
 
diff --git a/src/modules/systemlib/param/param.c b/src/modules/systemlib/param/param.c
index 9eb93e7035..633ca87617 100644
--- a/src/modules/systemlib/param/param.c
+++ b/src/modules/systemlib/param/param.c
@@ -111,8 +111,8 @@ static const struct param_info_s *param_info_base = (const struct param_info_s *
  * Storage for modified parameters.
  */
 struct param_wbuf_s {
-	param_t			param;
 	union param_value_u	val;
+	param_t			param;
 	bool			unsaved;
 };
 
diff --git a/src/modules/systemlib/param/param.h b/src/modules/systemlib/param/param.h
index 630280d7a6..61230aab56 100644
--- a/src/modules/systemlib/param/param.h
+++ b/src/modules/systemlib/param/param.h
@@ -69,23 +69,50 @@ typedef enum param_type_e {
 	PARAM_TYPE_UNKNOWN = 0xffff
 } param_type_t;
 
+
+#ifdef __PX4_NUTTX // on NuttX use 16 bits to save RAM
 /**
  * Parameter handle.
  *
  * Parameters are represented by parameter handles, which can
- * be obtained by looking up (or creating?) parameters.
+ * be obtained by looking up parameters. They are an offset into a global
+ * constant parameter array.
  */
-typedef uintptr_t	param_t;
+typedef uint16_t	param_t;
 
 /**
  * Handle returned when a parameter cannot be found.
  */
-#define PARAM_INVALID	((uintptr_t)0xffffffff)
+#define PARAM_INVALID	((uint16_t)0xffff)
 
 /**
  * Magic handle for hash check param
  */
-#define PARAM_HASH      ((uintptr_t)INT32_MAX)
+#define PARAM_HASH      ((uint16_t)INT16_MAX)
+
+#else // on other platforms use 32 bits for better performance
+
+/**
+ * Parameter handle.
+ *
+ * Parameters are represented by parameter handles, which can
+ * be obtained by looking up parameters. They are an offset into a global
+ * constant parameter array.
+ */
+typedef uint32_t	param_t;
+
+/**
+ * Handle returned when a parameter cannot be found.
+ */
+#define PARAM_INVALID	((uint32_t)0xffffffff)
+
+/**
+ * Magic handle for hash check param
+ */
+#define PARAM_HASH      ((uint32_t)INT32_MAX)
+
+#endif /* __PX4_NUTTX */
+
 
 /**
  * Initialize the param backend. Call this on startup before calling any other methods.
diff --git a/src/modules/systemlib/param/param_shmem.c b/src/modules/systemlib/param/param_shmem.c
index 23ae13a6a5..9dfe1bd0cc 100644
--- a/src/modules/systemlib/param/param_shmem.c
+++ b/src/modules/systemlib/param/param_shmem.c
@@ -96,8 +96,8 @@ static struct param_info_s *param_info_base = (struct param_info_s *) &px4_param
  * Storage for modified parameters.
  */
 struct param_wbuf_s {
-	param_t			param;
 	union param_value_u	val;
+	param_t			param;
 	bool			unsaved;
 };
 
diff --git a/src/platforms/posix/px4_layer/shmem_posix.c b/src/platforms/posix/px4_layer/shmem_posix.c
index 66cf5ba9bf..5811d89115 100644
--- a/src/platforms/posix/px4_layer/shmem_posix.c
+++ b/src/platforms/posix/px4_layer/shmem_posix.c
@@ -61,8 +61,8 @@ uint64_t update_from_shmem_prev_time = 0, update_from_shmem_current_time = 0;
 extern unsigned char *adsp_changed_index;
 
 struct param_wbuf_s {
-	param_t param;
 	union param_value_u val;
+	param_t param;
 	bool unsaved;
 };
 
diff --git a/src/platforms/qurt/px4_layer/shmem_qurt.c b/src/platforms/qurt/px4_layer/shmem_qurt.c
index 082048dd55..af62109712 100644
--- a/src/platforms/qurt/px4_layer/shmem_qurt.c
+++ b/src/platforms/qurt/px4_layer/shmem_qurt.c
@@ -77,8 +77,8 @@ static unsigned log2_for_int(unsigned v)
 }
 
 struct param_wbuf_s {
-	param_t param;
 	union param_value_u val;
+	param_t param;
 	bool unsaved;
 };
 extern struct param_wbuf_s *param_find_changed(param_t param);
diff --git a/src/systemcmds/param/param.c b/src/systemcmds/param/param.c
index dbb8439a34..934fb48043 100644
--- a/src/systemcmds/param/param.c
+++ b/src/systemcmds/param/param.c
@@ -368,7 +368,7 @@ do_find(const char *name)
 		return 1;
 	}
 
-	PARAM_PRINT("Found param %s at index %" PRIxPTR "\n", name, ret);
+	PARAM_PRINT("Found param %s at index %i\n", name, (int)ret);
 	return 0;
 }
 
diff --git a/unittests/param_test.cpp b/unittests/param_test.cpp
index 754d7fdb24..986e0d4902 100644
--- a/unittests/param_test.cpp
+++ b/unittests/param_test.cpp
@@ -54,8 +54,8 @@ void _assert_parameter_int_value(param_t param, int32_t expected)
 {
 	int32_t value;
 	int result = param_get(param, &value);
-	ASSERT_EQ(0, result) << printf("param_get (%lu) did not return parameter\n", param);
-	ASSERT_EQ(expected, value) << printf("value for param (%lu) doesn't match default value\n", param);
+	ASSERT_EQ(0, result) << printf("param_get (%i) did not return parameter\n", (int)param);
+	ASSERT_EQ(expected, value) << printf("value for param (%i) doesn't match default value\n", (int)param);
 }
 
 void _set_all_int_parameters_to(int32_t value)