diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 538b55703..a6d49d441 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -23,9 +23,9 @@
 # All executables link against libvillas
 link_libraries(villas)
 
-add_executable(villas-node villas-node.c)
-add_executable(villas-test-rtt villas-test-rtt.c)
-add_executable(villas-test-shmem villas-test-shmem.c)
+add_executable(villas-node villas-node.cpp)
+add_executable(villas-test-rtt villas-test-rtt.cpp)
+add_executable(villas-test-shmem villas-test-shmem.cpp)
 
 install(
     TARGETS villas-node villas-test-rtt villas-test-shmem
@@ -34,10 +34,10 @@ install(
 )
 
 if(WITH_IO)
-    add_executable(villas-test-cmp villas-test-cmp.c)
-    add_executable(villas-convert villas-convert.c)
-    add_executable(villas-pipe villas-pipe.c)
-    add_executable(villas-signal villas-signal.c)
+    add_executable(villas-test-cmp villas-test-cmp.cpp)
+    add_executable(villas-convert villas-convert.cpp)
+    add_executable(villas-pipe villas-pipe.cpp)
+    add_executable(villas-signal villas-signal.cpp)
 
     target_link_libraries(villas-pipe PUBLIC Threads::Threads)
 
@@ -49,7 +49,7 @@ if(WITH_IO)
 endif()
 
 if(WITH_IO AND WITH_HOOKS)
-    add_executable(villas-hook villas-hook.c)
+    add_executable(villas-hook villas-hook.cpp)
 
     install(
         TARGETS villas-hook
diff --git a/src/villas-convert.c b/src/villas-convert.cpp
similarity index 94%
rename from src/villas-convert.c
rename to src/villas-convert.cpp
index b02852851..204326fe9 100644
--- a/src/villas-convert.c
+++ b/src/villas-convert.cpp
@@ -45,8 +45,8 @@ static void usage()
 int main(int argc, char *argv[])
 {
 	int ret, level = V;
-	char *input_format = "villas.human";
-	char *output_format = "villas.human";
+	const char *input_format = "villas.human";
+	const char *output_format = "villas.human";
 
 	char c, *endptr;
 	while ((c = getopt(argc, argv, "Vhd:i:o:")) != -1) {
@@ -94,14 +94,14 @@ check:		if (optarg == endptr)
 		error("Failed to start log");
 
 	struct {
-		char *name;
+		const char *name;
 		struct io *io;
 	} dirs[] = {
 		{ input_format, &input },
 		{ output_format, &output },
 	};
 
-	for (int i = 0; i < ARRAY_LEN(dirs); i++) {
+	for (unsigned i = 0; i < ARRAY_LEN(dirs); i++) {
 		fmt = format_type_lookup(dirs[i].name);
 		if (!fmt)
 			error("Invalid format: %s", dirs[i].name);
@@ -127,7 +127,7 @@ check:		if (optarg == endptr)
 		io_print(&output, &smp, 1);
 	}
 
-	for (int i = 0; i < ARRAY_LEN(dirs); i++) {
+	for (unsigned i = 0; i < ARRAY_LEN(dirs); i++) {
 		ret = io_close(dirs[i].io);
 		if (ret)
 			error("Failed to close IO");
diff --git a/src/villas-hook.c b/src/villas-hook.cpp
similarity index 98%
rename from src/villas-hook.c
rename to src/villas-hook.cpp
index ecf31cf9f..e8e2226e8 100644
--- a/src/villas-hook.c
+++ b/src/villas-hook.cpp
@@ -111,7 +111,7 @@ static void usage()
 int main(int argc, char *argv[])
 {
 	int ret, recv, sent;
-	char *format = "villas.human";
+	const char *format = "villas.human";
 
 	struct format_type *ft;
 	struct hook_type *ht;
@@ -180,7 +180,7 @@ check:		if (optarg == endptr)
 	if (ret)
 		error("Failed to initialize memory");
 
-	smps = alloc(cnt * sizeof(struct sample *));
+	smps = (struct sample **) alloc(cnt * sizeof(struct sample *));
 
 	ret = pool_init(&q, 10 * cnt, SAMPLE_LEN(DEFAULT_SAMPLELEN), &memtype_hugepage);
 	if (ret)
diff --git a/src/villas-node.c b/src/villas-node.cpp
similarity index 99%
rename from src/villas-node.c
rename to src/villas-node.cpp
index f5de8d1c5..22b9c553c 100644
--- a/src/villas-node.c
+++ b/src/villas-node.cpp
@@ -113,7 +113,7 @@ int main(int argc, char *argv[])
 
 	opal_register_region(argc, argv);
 
-	char *uri = "opal-shmem.conf";
+	const char *uri = "opal-shmem.conf";
 #else
 	char c;
 	while ((c = getopt(argc, argv, "hV")) != -1) {
diff --git a/src/villas-pipe.c b/src/villas-pipe.cpp
similarity index 98%
rename from src/villas-pipe.c
rename to src/villas-pipe.cpp
index 7b387645e..3eadd704f 100644
--- a/src/villas-pipe.c
+++ b/src/villas-pipe.cpp
@@ -232,12 +232,13 @@ int main(int argc, char *argv[])
 {
 	int ret, level = V, timeout = 0;
 	bool reverse = false;
-	char *format = "villas.human";
+	const char *format = "villas.human";
 
-	sendd = recvv = (struct dir) {
-		.enabled = true,
-		.limit = -1
-	};
+	sendd.enabled = true;
+	sendd.limit = -1;
+	
+	recvv.enabled = true;
+	recvv.limit = -1;
 
 	json_t *cfg_cli = json_object();
 
@@ -337,7 +338,7 @@ check:		if (optarg == endptr)
 	if (ret)
 		error("Failed to open IO");
 
-	node = list_lookup(&sn.nodes, nodestr);
+	node = (struct node *) list_lookup(&sn.nodes, nodestr);
 	if (!node)
 		error("Node '%s' does not exist!", nodestr);
 
diff --git a/src/villas-signal.c b/src/villas-signal.cpp
similarity index 98%
rename from src/villas-signal.c
rename to src/villas-signal.cpp
index 324f12733..1a3d3011c 100644
--- a/src/villas-signal.c
+++ b/src/villas-signal.cpp
@@ -42,7 +42,6 @@ struct node n;
 struct log l;
 struct io io;
 struct pool q;
-
 struct sample *t;
 
 void usage()
@@ -111,7 +110,7 @@ int main(int argc, char *argv[])
 	struct node_type *nt;
 	struct format_type *ft;
 
-	char *format = "villas.human"; /** @todo hardcoded for now */
+	const char *format = "villas.human"; /** @todo hardcoded for now */
 
 	ret = log_init(&l, l.level, LOG_ALL);
 	if (ret)
diff --git a/src/villas-test-cmp.c b/src/villas-test-cmp.cpp
similarity index 98%
rename from src/villas-test-cmp.c
rename to src/villas-test-cmp.cpp
index 0c5bad66e..301010edf 100644
--- a/src/villas-test-cmp.c
+++ b/src/villas-test-cmp.cpp
@@ -35,7 +35,7 @@
 
 struct side {
 	char *path;
-	char *format;
+	const char *format;
 
 	struct sample *sample;
 
@@ -75,7 +75,7 @@ int main(int argc, char *argv[])
 
 	/* Default values */
 	double epsilon = 1e-9;
-	char *format = "villas.human";
+	const char *format = "villas.human";
 	int flags = SAMPLE_HAS_SEQUENCE | SAMPLE_HAS_VALUES | SAMPLE_HAS_ORIGIN;
 
 	struct pool pool = { .state = STATE_DESTROYED };
diff --git a/src/villas-test-rtt.c b/src/villas-test-rtt.cpp
similarity index 98%
rename from src/villas-test-rtt.c
rename to src/villas-test-rtt.cpp
index 051be9ed9..0599136ed 100644
--- a/src/villas-test-rtt.c
+++ b/src/villas-test-rtt.cpp
@@ -131,7 +131,7 @@ check:		if (optarg == endptr)
 	rt_init(sn.priority, sn.affinity);
 	memory_init(sn.hugepages);
 
-	node = list_lookup(&sn.nodes, nodestr);
+	node = (struct node *) list_lookup(&sn.nodes, nodestr);
 	if (!node)
 		error("There's no node with the name '%s'", nodestr);
 
diff --git a/src/villas-test-shmem.c b/src/villas-test-shmem.cpp
similarity index 98%
rename from src/villas-test-shmem.c
rename to src/villas-test-shmem.cpp
index 4e1747dcd..f3e89c3fa 100644
--- a/src/villas-test-shmem.c
+++ b/src/villas-test-shmem.cpp
@@ -55,9 +55,9 @@ int main(int argc, char* argv[])
 	struct log log;
 	int readcnt, writecnt, avail;
 	struct shmem_conf conf = {
-		.queuelen = DEFAULT_SHMEM_QUEUELEN,
-		.samplelen = DEFAULT_SHMEM_SAMPLELEN,
 		.polling = 0,
+		.queuelen = DEFAULT_SHMEM_QUEUELEN,
+		.samplelen = DEFAULT_SHMEM_SAMPLELEN
 	};
 
 	log_init(&log, V, LOG_ALL);