diff --git a/lib/hook.c b/lib/hook.c
index 1454ade14..94b85f118 100644
--- a/lib/hook.c
+++ b/lib/hook.c
@@ -224,9 +224,9 @@ int hook_parse_list(struct list *list, json_t *cfg, struct path *o, struct node
 	if (!json_is_array(cfg))
 		error("Hooks must be configured as a list of objects");
 
-	size_t index;
+	size_t i;
 	json_t *json_hook;
-	json_array_foreach(cfg, index, json_hook) {
+	json_array_foreach(cfg, i, json_hook) {
 		int ret;
 		const char *type;
 		struct hook_type *ht;
diff --git a/lib/nodes/cbuilder.c b/lib/nodes/cbuilder.c
index a2fb61dfe..e5af6c77c 100644
--- a/lib/nodes/cbuilder.c
+++ b/lib/nodes/cbuilder.c
@@ -21,7 +21,7 @@ int cbuilder_parse(struct node *n, json_t *cfg)
 	const char *model;
 
 	int ret;
-	size_t index;
+	size_t i;
 	json_error_t err;
 
 	ret = json_unpack_ex(cfg, &err, 0, "{ s: F, s: s, s: b }",
@@ -43,11 +43,11 @@ int cbuilder_parse(struct node *n, json_t *cfg)
 		cb->paramlen = json_array_size(json_params);
 		cb->params = alloc(cb->paramlen * sizeof(double));
 
-		json_array_foreach(json_params, index, json_param) {
+		json_array_foreach(json_params, i, json_param) {
 			if (json_is_number(json_param))
 				error("Setting 'parameters' of node %s must be an JSON array of numbers!", node_name(n));
 
-			cb->params[index] = json_number_value(json_params);
+			cb->params[i] = json_number_value(json_params);
 
 		}
 	}
diff --git a/lib/nodes/iec61850.c b/lib/nodes/iec61850.c
index 936f5467e..9b69b26f4 100644
--- a/lib/nodes/iec61850.c
+++ b/lib/nodes/iec61850.c
@@ -109,9 +109,9 @@ int iec61850_parse_mapping(json_t *json_mapping, struct list *mapping)
 
 	if (json_is_array(json_mapping)) {
 		json_t *json_field;
-		size_t index;
+		size_t i;
 
-		json_array_foreach(json_mapping, index, json_field) {
+		json_array_foreach(json_mapping, i, json_field) {
 			const struct iec61850_type_descriptor *m;
 			const char *type = json_string_value(json_field);
 
diff --git a/lib/nodes/nanomsg.c b/lib/nodes/nanomsg.c
index 57a0e76c2..b35b24581 100644
--- a/lib/nodes/nanomsg.c
+++ b/lib/nodes/nanomsg.c
@@ -50,12 +50,12 @@ static int nanomsg_parse_endpoints(struct list *l, json_t *cfg)
 {
 	const char *ep;
 
-	size_t index;
+	size_t i;
 	json_t *json_val;
 
 	switch (json_typeof(cfg)) {
 		case JSON_ARRAY:
-			json_array_foreach(cfg, index, json_val) {
+			json_array_foreach(cfg, i, json_val) {
 				ep = json_string_value(json_val);
 				if (!ep)
 					return -1;
diff --git a/lib/nodes/ngsi.c b/lib/nodes/ngsi.c
index a4d8d896a..0bd5fc0f2 100644
--- a/lib/nodes/ngsi.c
+++ b/lib/nodes/ngsi.c
@@ -124,7 +124,7 @@ static int ngsi_parse_entity(json_t *entity, struct ngsi *i, struct sample *smps
 	int ret;
 	const char *id, *name, *type;
 
-	size_t index;
+	size_t l;
 	json_t *attribute, *attributes;
 
 	ret = json_unpack(entity, "{ s: s, s: s, s: o }",
@@ -141,7 +141,7 @@ static int ngsi_parse_entity(json_t *entity, struct ngsi *i, struct sample *smps
 	for (int k = 0; k < cnt; k++)
 		smps[k]->length = json_array_size(attributes);
 
-	json_array_foreach(attributes, index, attribute) {
+	json_array_foreach(attributes, l, attribute) {
 		struct ngsi_attribute *map;
 		json_t *metadata, *values, *tuple;
 
@@ -203,10 +203,10 @@ static int ngsi_parse_mapping(struct list *mapping, json_t *cfg)
 
 	list_init(mapping);
 
-	size_t index;
+	size_t j;
 	json_t *json_token;
 
-	json_array_foreach(cfg, index, json_token) {
+	json_array_foreach(cfg, j, json_token) {
 		const char *token;
 
 		token = json_string_value(json_token);
@@ -215,7 +215,7 @@ static int ngsi_parse_mapping(struct list *mapping, json_t *cfg)
 
 		struct ngsi_attribute *a = (struct ngsi_attribute *) alloc(sizeof(struct ngsi_attribute));
 
-		a->index = index;
+		a->index = j;
 
 		/* Parse Attribute: AttributeName(AttributeType) */
 		int bytes;
@@ -245,7 +245,7 @@ static int ngsi_parse_mapping(struct list *mapping, json_t *cfg)
 			.name = "index",
 			.type = "integer"
 		};
-		assert(asprintf(&i.value, "%zu", index));
+		assert(asprintf(&i.value, "%zu", j));
 
 		list_push(&a->metadata, memdup(&s, sizeof(s)));
 		list_push(&a->metadata, memdup(&i, sizeof(i)));
diff --git a/lib/nodes/shmem.c b/lib/nodes/shmem.c
index 23666cfb9..d3f3689a9 100644
--- a/lib/nodes/shmem.c
+++ b/lib/nodes/shmem.c
@@ -67,17 +67,17 @@ int shmem_parse(struct node *n, json_t *cfg)
 
 		shm->exec = alloc(sizeof(char *) * (json_array_size(json_exec) + 1));
 
-		size_t index;
+		size_t i;
 		json_t *json_val;
-		json_array_foreach(json_exec, index, json_val) {
+		json_array_foreach(json_exec, i, json_val) {
 			val = json_string_value(json_val);
 			if (!val)
 				error("Setting 'exec' of node %s must be an array of strings", node_name(n));
 
-			shm->exec[index] = strdup(val);
+			shm->exec[i] = strdup(val);
 		}
 
-		shm->exec[index] = NULL;
+		shm->exec[i] = NULL;
 	}
 
 	return 0;
diff --git a/lib/nodes/test_rtt.c b/lib/nodes/test_rtt.c
index 8240c695d..5cea6a0c5 100644
--- a/lib/nodes/test_rtt.c
+++ b/lib/nodes/test_rtt.c
@@ -83,7 +83,7 @@ int test_rtt_parse(struct node *n, json_t *cfg)
 	int numrates = 0;
 	int numvalues = 0;
 
-	size_t index;
+	size_t i;
 	json_t *json_cases, *json_case, *json_val;
 	json_t *json_rates = NULL, *json_values = NULL;
 	json_error_t err;
@@ -116,7 +116,7 @@ int test_rtt_parse(struct node *n, json_t *cfg)
 	if (!json_is_array(json_cases))
 		error("The 'cases' setting of node %s must be an array.", node_name(n));
 
-	json_array_foreach(json_cases, index, json_case) {
+	json_array_foreach(json_cases, i, json_case) {
 		int limit = -1;
 		double duration = -1; /* in secs */
 
@@ -148,23 +148,25 @@ int test_rtt_parse(struct node *n, json_t *cfg)
 		values = realloc(values, sizeof(values[0]) * numvalues);
 
 		if (json_is_array(json_rates)) {
-			json_array_foreach(json_rates, index, json_val) {
+			size_t j;
+			json_array_foreach(json_rates, j, json_val) {
 				if (!json_is_number(json_val))
 					error("The 'rates' setting of node %s must be an array of real numbers", node_name(n));
 
-				rates[index] = json_integer_value(json_val);
+				rates[i] = json_integer_value(json_val);
 			}
 		}
 		else
 			rates[0] = json_number_value(json_rates);
 
 		if (json_is_array(json_values)) {
-			json_array_foreach(json_values, index, json_val) {
+			size_t j;
+			json_array_foreach(json_values, j, json_val) {
 				if (!json_is_integer(json_val))
 					error("The 'values' setting of node %s must be an array of integers", node_name(n));
 
-				values[index] = json_integer_value(json_val);
-				if (values[index] < 2)
+				values[j] = json_integer_value(json_val);
+				if (values[j] < 2)
 					error("Each 'values' entry must be at least 2 or larger");
 			}
 		}
diff --git a/lib/nodes/websocket.c b/lib/nodes/websocket.c
index 4fa3849c3..2b1ceb4f3 100644
--- a/lib/nodes/websocket.c
+++ b/lib/nodes/websocket.c
@@ -517,7 +517,7 @@ int websocket_parse(struct node *n, json_t *cfg)
 	struct websocket *w = (struct websocket *) n->_vd;
 	int ret;
 
-	size_t index;
+	size_t i;
 	json_t *json_dests = NULL;
 	json_t *json_dest;
 	json_error_t err;
@@ -532,7 +532,7 @@ int websocket_parse(struct node *n, json_t *cfg)
 		if (!json_is_array(json_dests))
 			error("The 'destinations' setting of node %s must be an array of URLs", node_name(n));
 
-		json_array_foreach(json_dests, index, json_dest) {
+		json_array_foreach(json_dests, i, json_dest) {
 			const char *uri, *prot, *ads, *path;
 
 			uri = json_string_value(json_dest);
diff --git a/lib/nodes/zeromq.c b/lib/nodes/zeromq.c
index 55c019867..e439f0d6e 100644
--- a/lib/nodes/zeromq.c
+++ b/lib/nodes/zeromq.c
@@ -101,7 +101,7 @@ int zeromq_parse(struct node *n, json_t *cfg)
 	const char *filter = NULL;
 	const char *format = "villas.human";
 
-	size_t index;
+	size_t i;
 	json_t *json_pub = NULL;
 	json_t *json_curve = NULL;
 	json_t *json_val;
@@ -134,7 +134,7 @@ int zeromq_parse(struct node *n, json_t *cfg)
 	if (json_pub) {
 		switch (json_typeof(json_pub)) {
 			case JSON_ARRAY:
-				json_array_foreach(json_pub, index, json_val) {
+				json_array_foreach(json_pub, i, json_val) {
 					ep = json_string_value(json_pub);
 					if (!ep)
 						error("All 'publish' settings must be strings");
diff --git a/lib/signal.c b/lib/signal.c
index 4728f9040..679cb5aee 100644
--- a/lib/signal.c
+++ b/lib/signal.c
@@ -149,9 +149,9 @@ int signal_parse_list(struct list *list, json_t *cfg)
 	if (!json_is_array(cfg))
 		return -1;
 
-	size_t index;
+	size_t i;
 	json_t *json_signal;
-	json_array_foreach(cfg, index, json_signal) {
+	json_array_foreach(cfg, i, json_signal) {
 		s = alloc(sizeof(struct signal));
 		if (!s)
 			return -1;
diff --git a/lib/super_node.c b/lib/super_node.c
index a66c93452..d6e101842 100644
--- a/lib/super_node.c
+++ b/lib/super_node.c
@@ -220,9 +220,9 @@ int super_node_parse_json(struct super_node *sn, json_t *cfg)
 		if (!json_is_array(json_plugins))
 			error("Setting 'plugins' must be a list of strings");
 
-		size_t index;
+		size_t i;
 		json_t *json_plugin;
-		json_array_foreach(json_plugins, index, json_plugin) {
+		json_array_foreach(json_plugins, i, json_plugin) {
 			struct plugin *p = (struct plugin *) alloc(sizeof(struct plugin));
 
 			ret = plugin_init(p);
@@ -275,9 +275,9 @@ int super_node_parse_json(struct super_node *sn, json_t *cfg)
 		if (!json_is_array(json_paths))
 			warn("Setting 'paths' must be a list.");
 
-		size_t index;
+		size_t i;
 		json_t *json_path;
-		json_array_foreach(json_paths, index, json_path) {
+		json_array_foreach(json_paths, i, json_path) {
 			struct path *p = (struct path *) alloc(sizeof(struct path));
 
 			ret = path_init(p);