diff --git a/topology/pre-processor.c b/topology/pre-processor.c
index e6f9af6..b0353bb 100644
--- a/topology/pre-processor.c
+++ b/topology/pre-processor.c
@@ -222,7 +222,93 @@ err:
 	return ret;
 }
 
-int pre_process(struct tplg_pre_processor *tplg_pp, char *config, size_t config_size)
+static int pre_process_defines(struct tplg_pre_processor *tplg_pp, const char *pre_processor_defs,
+			       snd_config_t *top)
+{
+	snd_config_t *conf_defines, *defines;
+	int ret;
+
+	ret = snd_config_search(tplg_pp->input_cfg, "Define", &conf_defines);
+	if (ret < 0)
+		return 0;
+
+	if (snd_config_get_type(conf_defines) != SND_CONFIG_TYPE_COMPOUND)
+		return 0;
+
+	/*
+	 * load and merge the command line defines with the variables in the conf file to override
+	 * default values
+	 */
+	if (pre_processor_defs != NULL) {
+		ret = snd_config_load_string(&defines, pre_processor_defs, strlen(pre_processor_defs));
+		if (ret < 0) {
+			fprintf(stderr, "Failed to load pre-processor command line definitions\n");
+			return ret;
+		}
+
+		ret = snd_config_merge(conf_defines, defines, true);
+		if (ret < 0) {
+			fprintf(stderr, "Failed to override variable definitions\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int pre_process_variables_expand_fcn(snd_config_t **dst, const char *str,
+					    void *private_data)
+{
+	struct tplg_pre_processor *tplg_pp = private_data;
+	snd_config_iterator_t i, next;
+	snd_config_t *conf_defines;
+	int ret;
+
+	ret = snd_config_search(tplg_pp->input_cfg, "Define", &conf_defines);
+	if (ret < 0)
+		return 0;
+
+	/* find variable definition */
+	snd_config_for_each(i, next, conf_defines) {
+		snd_config_t *n;
+		const char *id;
+
+		n = snd_config_iterator_entry(i);
+		if (snd_config_get_id(n, &id) < 0)
+			continue;
+
+		if (strcmp(id, str))
+			continue;
+
+		/* found definition. Match type and return appropriate config */
+		if (snd_config_get_type(n) == SND_CONFIG_TYPE_STRING) {
+			const char *s;
+
+			if (snd_config_get_string(n, &s) < 0)
+				continue;
+
+			return snd_config_imake_string(dst, NULL, s);
+		}
+
+		if (snd_config_get_type(n) == SND_CONFIG_TYPE_INTEGER) {
+			long v;
+
+			if (snd_config_get_integer(n, &v) < 0)
+				continue;
+
+			ret = snd_config_imake_integer(dst, NULL, v);
+			return ret;
+		}
+
+	}
+
+	fprintf(stderr, "No definition for variable %s\n", str);
+
+	return -EINVAL;
+}
+
+int pre_process(struct tplg_pre_processor *tplg_pp, char *config, size_t config_size,
+		const char *pre_processor_defs)
 {
 	snd_input_t *in;
 	snd_config_t *top;
@@ -249,7 +335,22 @@ int pre_process(struct tplg_pre_processor *tplg_pp, char *config, size_t config_
 
 	tplg_pp->input_cfg = top;
 
-	err = pre_process_config(tplg_pp, top);
+	/* parse command line definitions */
+	err = pre_process_defines(tplg_pp, pre_processor_defs, tplg_pp->input_cfg);
+	if (err < 0) {
+		fprintf(stderr, "Failed to parse arguments in input config\n");
+		goto err;
+	}
+
+	/* expand pre-processor variables */
+	err = snd_config_expand_custom(tplg_pp->input_cfg, tplg_pp->input_cfg, pre_process_variables_expand_fcn,
+				       tplg_pp, &tplg_pp->input_cfg);
+	if (err < 0) {
+		fprintf(stderr, "Failed to expand pre-processor definitions in input config\n");
+		goto err;
+	}
+
+	err = pre_process_config(tplg_pp, tplg_pp->input_cfg);
 	if (err < 0) {
 		fprintf(stderr, "Unable to pre-process configuration\n");
 		goto err;
diff --git a/topology/topology.c b/topology/topology.c
index e0c7e7c..4a0750f 100644
--- a/topology/topology.c
+++ b/topology/topology.c
@@ -234,7 +234,8 @@ static int dump(const char *source_file, const char *output_file, int cflags, in
 }
 
 /* Convert Topology2.0 conf to the existing conf syntax */
-static int pre_process_conf(const char *source_file, const char *output_file)
+static int pre_process_conf(const char *source_file, const char *output_file,
+			    const char *pre_processor_defs)
 {
 	struct tplg_pre_processor *tplg_pp;
 	size_t config_size;
@@ -254,7 +255,7 @@ static int pre_process_conf(const char *source_file, const char *output_file)
 	}
 
 	/* pre-process conf file */
-	err = pre_process(tplg_pp, config, config_size);
+	err = pre_process(tplg_pp, config, config_size, pre_processor_defs);
 
 	/* free pre-processor */
 	free_pre_preprocessor(tplg_pp);
@@ -262,7 +263,8 @@ static int pre_process_conf(const char *source_file, const char *output_file)
 	return err;
 }
 
-static int compile(const char *source_file, const char *output_file, int cflags)
+static int compile(const char *source_file, const char *output_file, int cflags,
+		   const char *pre_processor_defs)
 {
 	struct tplg_pre_processor *tplg_pp = NULL;
 	snd_tplg_t *tplg;
@@ -284,7 +286,7 @@ static int compile(const char *source_file, const char *output_file, int cflags)
 		init_pre_precessor(&tplg_pp, SND_OUTPUT_BUFFER, NULL);
 
 		/* pre-process conf file */
-		err = pre_process(tplg_pp, config, config_size);
+		err = pre_process(tplg_pp, config, config_size, pre_processor_defs);
 		if (err) {
 			free_pre_preprocessor(tplg_pp);
 			free(config);
@@ -353,7 +355,7 @@ static int decode(const char *source_file, const char *output_file,
 
 int main(int argc, char *argv[])
 {
-	static const char short_options[] = "hc:d:n:u:v:o:pP:sgxzV";
+	static const char short_options[] = "hc:d:n:u:v:o:pP:sgxzVD:";
 	static const struct option long_options[] = {
 		{"help", 0, NULL, 'h'},
 		{"verbose", 1, NULL, 'v'},
@@ -372,6 +374,7 @@ int main(int argc, char *argv[])
 	};
 	char *source_file = NULL;
 	char *output_file = NULL;
+	const char *pre_processor_defs = NULL;
 	int c, err, op = 'c', cflags = 0, dflags = 0, sflags = 0, option_index;
 
 #ifdef ENABLE_NLS
@@ -423,6 +426,9 @@ int main(int argc, char *argv[])
 		case 'x':
 			sflags |= SND_TPLG_SAVE_NOCHECK;
 			break;
+		case 'D':
+			pre_processor_defs = optarg;
+			break;
 		case 'V':
 			version(argv[0]);
 			return 0;
@@ -448,13 +454,13 @@ int main(int argc, char *argv[])
 
 	switch (op) {
 	case 'c':
-		err = compile(source_file, output_file, cflags);
+		err = compile(source_file, output_file, cflags, pre_processor_defs);
 		break;
 	case 'd':
 		err = decode(source_file, output_file, cflags, dflags, sflags);
 		break;
 	case 'P':
-		err = pre_process_conf(source_file, output_file);
+		err = pre_process_conf(source_file, output_file, pre_processor_defs);
 		break;
 	default:
 		err = dump(source_file, output_file, cflags, sflags);
diff --git a/topology/topology.h b/topology/topology.h
index 494612b..5dd9b1f 100644
--- a/topology/topology.h
+++ b/topology/topology.h
@@ -27,7 +27,8 @@ struct tplg_pre_processor {
 	snd_output_t *dbg_output;
 };
 
-int pre_process(struct tplg_pre_processor *tplg_pp, char *config, size_t config_size);
+int pre_process(struct tplg_pre_processor *tplg_pp, char *config, size_t config_size,
+		const char *pre_processor_defs);
 int init_pre_precessor(struct tplg_pre_processor **tplg_pp, snd_output_type_t type,
 		       const char *output_file);
 void free_pre_preprocessor(struct tplg_pre_processor *tplg_pp);