diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
index d13fc1dfd5ef..4d01051951cd 100644
--- a/tools/perf/tests/expr.c
+++ b/tools/perf/tests/expr.c
@@ -18,8 +18,9 @@ static int test(struct expr_parse_ctx *ctx, const char *e, double val2)
 
 int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
 {
+	struct expr_id_data *val_ptr;
 	const char *p;
-	double val, *val_ptr;
+	double val;
 	int ret;
 	struct expr_parse_ctx ctx;
 
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 9116a3a01eea..5d05f9765ed8 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -33,32 +33,32 @@ static bool key_equal(const void *key1, const void *key2,
 }
 
 /* Caller must make sure id is allocated */
-int expr__add_id_val(struct expr_parse_ctx *ctx, const char *name, double val)
+int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
 {
-	double *val_ptr = NULL, *old_val = NULL;
+	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
 	char *old_key = NULL;
 	int ret;
 
 	if (val != 0.0) {
-		val_ptr = malloc(sizeof(double));
-		if (!val_ptr)
+		data_ptr = malloc(sizeof(*data_ptr));
+		if (!data_ptr)
 			return -ENOMEM;
-		*val_ptr = val;
+		data_ptr->val = val;
 	}
-	ret = hashmap__set(&ctx->ids, name, val_ptr,
-			   (const void **)&old_key, (void **)&old_val);
+	ret = hashmap__set(&ctx->ids, id, data_ptr,
+			   (const void **)&old_key, (void **)&old_data);
 	free(old_key);
-	free(old_val);
+	free(old_data);
 	return ret;
 }
 
 int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr)
 {
-	double *data;
+	struct expr_id_data *data;
 
 	if (!hashmap__find(&ctx->ids, id, (void **)&data))
 		return -1;
-	*val_ptr = (data == NULL) ?  0.0 : *data;
+	*val_ptr = (data == NULL) ?  0.0 : data->val;
 	return 0;
 }
 
@@ -119,7 +119,7 @@ int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
 int expr__find_other(const char *expr, const char *one,
 		     struct expr_parse_ctx *ctx, int runtime)
 {
-	double *old_val = NULL;
+	struct expr_id_data *old_val = NULL;
 	char *old_key = NULL;
 	int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
 
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index bb6bac836b48..21fe5bd85718 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -15,6 +15,10 @@ struct expr_parse_ctx {
 	struct hashmap ids;
 };
 
+struct expr_id_data {
+	double	val;
+};
+
 struct expr_scanner_ctx {
 	int start_token;
 	int runtime;
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 82fecb5a302d..df0356ec120d 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -138,7 +138,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
 				      unsigned long *evlist_used)
 {
 	struct evsel *ev, *current_leader = NULL;
-	double *val_ptr;
+	struct expr_id_data *val_ptr;
 	int i = 0, matched_events = 0, events_to_match;
 	const int idnum = (int)hashmap__size(&pctx->ids);