diff --git a/src/misc/debug.c b/src/misc/debug.c
index 8f53d1ad7..8a88f14e0 100644
--- a/src/misc/debug.c
+++ b/src/misc/debug.c
@@ -49,7 +49,7 @@
 double timestamp(void)
 {
 	struct timeval tv;
-	gettimeofday(&tv, 0); // more accurate than <time.h>
+	gettimeofday(&tv, NULL); // more accurate than <time.h>
 
 	return (double)tv.tv_sec + 1e-6 * (double)tv.tv_usec;
 }
diff --git a/src/moba/recon.c b/src/moba/recon.c
index 012d1acaf..ba9b67df3 100644
--- a/src/moba/recon.c
+++ b/src/moba/recon.c
@@ -294,7 +294,7 @@ static void recon(const struct moba_conf* conf, struct moba_conf_s* data,
 	mconf.b = conf->sobolev_b;
 	mconf.cnstcoil_flags = TE_FLAG | CSHIFT_FLAG;
 
-	struct mobamod nl = { 0 };
+	struct mobamod nl = { };
 
 	switch (conf->mode) {
 
diff --git a/src/networks/nlinvnet.c b/src/networks/nlinvnet.c
index 2b3c55b53..c7ac42a40 100644
--- a/src/networks/nlinvnet.c
+++ b/src/networks/nlinvnet.c
@@ -379,8 +379,9 @@ static nn_t nlinvnet_get_network_step(const struct nlinvnet_s* nlinvnet, struct
 		auto dummy = nn_from_nlop_F(nlop_del_out_create(dom->N, dom->dims));
 		dummy = nn_set_input_name_F(dummy, 0, "ref_col");
 		
-		complex float zero[1] = { 0 };
-		join = nn_set_input_const_F2(join, 1, 0, dom->N, dom->dims, MD_SINGLETON_STRS(dom->N), true, zero);
+		complex float zero[1] = { 0. };
+
+		join = nn_set_input_const_F2(join, 1, NULL, dom->N, dom->dims, MD_SINGLETON_STRS(dom->N), true, zero);
 		join = nn_combine_FF(dummy, join);	
 	}
 
@@ -722,7 +723,7 @@ static nn_t nlinvnet_valid_create(const struct nlinvnet_s* nlinvnet, struct name
 	result = nn_chain2_FF(result, 0, NULL, nn_from_nlop_F(noir_decomp_create(model)), 0, NULL);
 
 	auto cim_iov = named_data_list_get_iovec(valid_data, "ref");
-	auto valid_loss = nn_chain2_FF(result, 0, 0, val_measure_create(nlinvnet->valid_loss, cim_iov->N, cim_iov->dims), 0, NULL);
+	auto valid_loss = nn_chain2_FF(result, 0, NULL, val_measure_create(nlinvnet->valid_loss, cim_iov->N, cim_iov->dims), 0, NULL);
 	iovec_free(cim_iov);
 
 	valid_loss = nn_set_input_name_F(valid_loss, 0, "ref");
diff --git a/src/nn/data_list.c b/src/nn/data_list.c
index fa2efa520..2142bdd1f 100644
--- a/src/nn/data_list.c
+++ b/src/nn/data_list.c
@@ -135,7 +135,7 @@ extern const struct nlop_s* nn_batchgen_create(struct bat_gen_conf_s* config, nn
 
 		if (IN_BATCH_GENERATOR == in_types[i]) {
 
-			assert(0 != names[i]);
+			assert(NULL != names[i]);
 
 			N = MAX(N, nn_generic_domain(network, 0, names[i])->N);
 			D++;
diff --git a/src/nn/nn.c b/src/nn/nn.c
index 649d286b8..7f78d75c7 100644
--- a/src/nn/nn.c
+++ b/src/nn/nn.c
@@ -794,7 +794,7 @@ void nn_export_graph(const char* filename, nn_t op)
 	FILE *fp;
 	fp = fopen(filename, "w+");
 
-	assert(0 != fp);
+	assert(NULL != fp);
 
 	fprintf(fp, "digraph {\nnewrank=true;\n");
 	fprintf(fp, "{\n%s}\n", str);
diff --git a/src/noncart/nufft_chain.c b/src/noncart/nufft_chain.c
index 08d0d4943..223c36f56 100644
--- a/src/noncart/nufft_chain.c
+++ b/src/noncart/nufft_chain.c
@@ -210,7 +210,7 @@ extern struct linop_s* nufft_create_chain(int N,
 	
 	ret = linop_chain_FF(ret, linop_fftc_create(N, os_cim_dims, flags));
 
-	if (0 != basis) {
+	if (NULL != basis) {
 
 		long ksp_max_dims[N];
 		md_max_dims(N, ~0UL, ksp_max_dims, ksp_dims, bas_dims);
@@ -218,6 +218,7 @@ extern struct linop_s* nufft_create_chain(int N,
 
 		ret = linop_chain_FF(ret, linop_interpolate_kb_create(N, flags, ksp_max_dims, os_cim_dims, traj_dims, traj, conf));
 		ret = linop_chain_FF(ret, linop_fmac_create(N, ksp_max_dims, ~md_nontriv_dims(N, ksp_dims), 0, ~md_nontriv_dims(N, bas_dims), basis));
+
 	} else {
 
 		ret = linop_chain_FF(ret, linop_interpolate_kb_create(N, flags, ksp_dims, os_cim_dims, traj_dims, traj, conf));
diff --git a/src/num/lapack.c b/src/num/lapack.c
index 872c7dafb..be2c2ffd2 100644
--- a/src/num/lapack.c
+++ b/src/num/lapack.c
@@ -134,7 +134,7 @@ void lapack_schur(long N, complex float W[N], complex float VS[N][N], complex fl
 	int sdim = 0;
 
 	// On output, A overwritten by Schur form T
-	LAPACKE(cgees, 'V', 'N', 0, N, &A[0][0], N, &sdim, &W[0], &VS[0][0], N);
+	LAPACKE(cgees, 'V', 'N', NULL, N, &A[0][0], N, &sdim, &W[0], &VS[0][0], N);
 }
 
 void lapack_schur_double(long N, complex double W[N], complex double VS[N][N], complex double A[N][N])
@@ -142,7 +142,7 @@ void lapack_schur_double(long N, complex double W[N], complex double VS[N][N], c
 	int sdim = 0;
 
 	// On output, A overwritten by Schur form T
-	LAPACKE(zgees, 'V', 'N', 0, N, &A[0][0], N, &sdim, &W[0], &VS[0][0], N);
+	LAPACKE(zgees, 'V', 'N', NULL, N, &A[0][0], N, &sdim, &W[0], &VS[0][0], N);
 }
 
 // Solves the complex Sylvester matrix equation
diff --git a/src/num/multind.c b/src/num/multind.c
index 7b20b05d9..51f31b166 100644
--- a/src/num/multind.c
+++ b/src/num/multind.c
@@ -2391,7 +2391,7 @@ void* md_alloc_sameplace(int D, const long dimensions[D], size_t size, const voi
 #ifdef USE_CUDA
 	return (cuda_ondevice(ptr) ? md_alloc_gpu : md_alloc)(D, dimensions, size);
 #else
-	assert(0 != ptr);
+	assert(NULL != ptr);
 	return md_alloc(D, dimensions, size);
 #endif
 }
diff --git a/src/num/vptr.c b/src/num/vptr.c
index ec3365ad9..79a4efee1 100644
--- a/src/num/vptr.c
+++ b/src/num/vptr.c
@@ -247,7 +247,7 @@ static struct mem_s* vptr_create(int N, const long dims[N], size_t size, struct
 {
 	long len = md_calc_size(N, dims) * (long)size;
 
-	void* ptr = mmap(0, (size_t)len, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+	void* ptr = mmap(NULL, (size_t)len, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
 
 	PTR_ALLOC(struct mem_s, x);