diff --git a/src/audio/module_adapter/module_adapter_ipc4.c b/src/audio/module_adapter/module_adapter_ipc4.c
index 5da830b1be53..81f7fca1d22d 100644
--- a/src/audio/module_adapter/module_adapter_ipc4.c
+++ b/src/audio/module_adapter/module_adapter_ipc4.c
@@ -167,22 +167,6 @@ int module_adapter_get_attribute(struct comp_dev *dev, uint32_t type, void *valu
 		memcpy_s(value, sizeof(struct ipc4_base_module_cfg),
 			 &mod->priv.cfg.base_cfg, sizeof(mod->priv.cfg.base_cfg));
 		break;
-	case COMP_ATTR_BASE_CONFIG_EXT:
-	{
-		struct ipc4_base_module_cfg_ext *basecfg_ext = mod->priv.cfg.basecfg_ext;
-		size_t size;
-
-		if (!basecfg_ext) {
-			comp_err(mod->dev, "No base config extn set for module");
-			return -EINVAL;
-		}
-
-		size = basecfg_ext->nb_input_pins * sizeof(struct ipc4_input_pin_format) +
-				basecfg_ext->nb_output_pins * sizeof(struct ipc4_output_pin_format);
-		memcpy_s(value, sizeof(*basecfg_ext) + size,
-			 basecfg_ext, sizeof(*basecfg_ext) + size);
-		break;
-	}
 	default:
 		return -EINVAL;
 	}
diff --git a/src/include/module/module/base.h b/src/include/module/module/base.h
index ef46b333984f..323599b055f2 100644
--- a/src/include/module/module/base.h
+++ b/src/include/module/module/base.h
@@ -34,8 +34,6 @@ struct module_config {
 	uint8_t nb_output_pins;
 	struct ipc4_input_pin_format *input_pins;
 	struct ipc4_output_pin_format *output_pins;
-	struct ipc4_base_module_cfg_ext *basecfg_ext; /* legacy API */
-
 #endif
 };
 
diff --git a/src/include/sof/audio/component.h b/src/include/sof/audio/component.h
index daafb8a5bb98..3896d2f55065 100644
--- a/src/include/sof/audio/component.h
+++ b/src/include/sof/audio/component.h
@@ -117,7 +117,6 @@ enum {
 #define COMP_ATTR_COPY_DIR	2	/**< Comp copy direction */
 #define COMP_ATTR_VDMA_INDEX	3	/**< Comp index of the virtual DMA at the gateway. */
 #define COMP_ATTR_BASE_CONFIG	4	/**< Component base config */
-#define COMP_ATTR_BASE_CONFIG_EXT 5	/**< Component base config extension */
 /** @}*/
 
 /** \name Trace macros
diff --git a/src/include/sof/audio/component_ext.h b/src/include/sof/audio/component_ext.h
index d7abce7b3d94..7d0a0c44dc78 100644
--- a/src/include/sof/audio/component_ext.h
+++ b/src/include/sof/audio/component_ext.h
@@ -230,8 +230,7 @@ static inline int comp_ipc4_get_attribute_remote(struct comp_dev *dev, uint32_t
 	payload.type = type;
 
 	/*
-	 * Only COMP_ATTR_BASE_CONFIG and COMP_ATTR_BASE_CONFIG_EXT are supported for
-	 * remote access
+	 * Only COMP_ATTR_BASE_CONFIG is supported for remote access
 	 */
 	switch (type) {
 	case COMP_ATTR_BASE_CONFIG:
@@ -242,14 +241,6 @@ static inline int comp_ipc4_get_attribute_remote(struct comp_dev *dev, uint32_t
 
 		payload.value = base_cfg;
 		break;
-	case COMP_ATTR_BASE_CONFIG_EXT:
-		basecfg_ext = rzalloc(SOF_MEM_ZONE_RUNTIME_SHARED, 0, SOF_MEM_CAPS_RAM,
-					  sizeof(*basecfg_ext) + size);
-		if (!basecfg_ext)
-			return -ENOMEM;
-
-		payload.value = basecfg_ext;
-		break;
 	default:
 		return -EINVAL;
 	}
@@ -263,10 +254,6 @@ static inline int comp_ipc4_get_attribute_remote(struct comp_dev *dev, uint32_t
 				 base_cfg, sizeof(struct ipc4_base_module_cfg));
 			rfree(base_cfg);
 			break;
-		case COMP_ATTR_BASE_CONFIG_EXT:
-			memcpy_s(value, size, basecfg_ext, size);
-			rfree(basecfg_ext);
-			break;
 		}
 	}
 
diff --git a/src/samples/audio/smart_amp_test_ipc4.c b/src/samples/audio/smart_amp_test_ipc4.c
index 31924781e666..001de7bbf5eb 100644
--- a/src/samples/audio/smart_amp_test_ipc4.c
+++ b/src/samples/audio/smart_amp_test_ipc4.c
@@ -100,16 +100,6 @@ static int smart_amp_init(struct processing_module *mod)
 		*(struct ipc4_output_pin_format *)(base_cfg->base_cfg_ext.pin_formats
 			+ sizeof(sad->ipc4_cfg.input_pins));
 
-	/* save the base config extension */
-	size = sizeof(struct ipc4_base_module_cfg_ext) + in_size + out_size;
-	mod_data->cfg.basecfg_ext = rzalloc(SOF_MEM_ZONE_RUNTIME, 0, SOF_MEM_CAPS_RAM, size);
-	if (!mod_data->cfg.basecfg_ext) {
-		ret = -ENOMEM;
-		goto sad_fail;
-	}
-
-	memcpy_s(mod_data->cfg.basecfg_ext, size, &base_cfg->base_cfg_ext, size);
-
 	return 0;
 
 sad_fail:
@@ -172,7 +162,6 @@ static int smart_amp_free(struct processing_module *mod)
 	struct module_data *mod_data = &mod->priv;
 	struct comp_dev *dev = mod->dev;
 
-	rfree(mod_data->cfg.basecfg_ext);
 	rfree(sad);
 #endif