diff --git a/cpucount.c b/cpucount.c
index db8832e..32f32ff 100644
--- a/cpucount.c
+++ b/cpucount.c
@@ -54,7 +54,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <strings.h>
-static int parsecpuinfo()
+static int parsecpuinfo(void)
 {
 	unsigned char cpubitmap[128];
 
diff --git a/filters.h b/filters.h
index efe24fb..26d2c9e 100644
--- a/filters.h
+++ b/filters.h
@@ -400,7 +400,7 @@ static void filters_add(const char *filter)
 		return;
 	}
 	// attempt to JIT. ignore error
-	(void)pcre2_jit_compile(re,PCRE2_JIT_COMPLETE);
+	(void) pcre2_jit_compile(re,PCRE2_JIT_COMPLETE);
 	struct pcre2filter f;
 	memset(&f,0,sizeof(f));
 	f.re = re;
@@ -414,13 +414,13 @@ static void filters_add(const char *filter)
 }
 
 #ifdef NEEDBINFILTER
-static void filters_dedup()
+static void filters_dedup(void)
 {
 	//TODO
 }
 #endif // NEEDBINFILTER
 
-static void filters_prepare()
+static void filters_prepare(void)
 {
 #ifndef PCRE2FILTER
 	if (!quietflag)
@@ -436,7 +436,7 @@ static void filters_prepare()
 #endif
 }
 
-static void filters_clean()
+static void filters_clean(void)
 {
 #ifdef PCRE2FILTER
 	for (size_t i = 0;i < VEC_LENGTH(filters);++i) {
@@ -447,7 +447,7 @@ static void filters_clean()
 	VEC_FREE(filters);
 }
 
-static size_t filters_count()
+static size_t filters_count(void)
 {
 	return VEC_LENGTH(filters);
 }
@@ -624,7 +624,7 @@ static void loadfilterfile(const char *fname)
 	}
 }
 
-static void filters_print()
+static void filters_print(void)
 {
 	if (quietflag)
 		return;
diff --git a/test_base16.c b/test_base16.c
index a4779f2..3f3aacd 100644
--- a/test_base16.c
+++ b/test_base16.c
@@ -30,7 +30,7 @@ struct texttestcase {
 	{"foobar", "666F6F626172", "foobar"},
 };
 
-int main()
+int main(void)
 {
 	char buf[1024], buf2[1024], mask;
 	size_t r;
diff --git a/test_base32.c b/test_base32.c
index 3a325fe..4347ff8 100644
--- a/test_base32.c
+++ b/test_base32.c
@@ -57,7 +57,7 @@ struct masktestcase {
 };
 */
 
-int main()
+int main(void)
 {
 	char buf[1024], buf2[1024], mask;
 	size_t r;
@@ -81,4 +81,4 @@ int main()
 	//fprintf(stderr, ">%s\n", buf2);
 	
 	return 0;
-}
\ No newline at end of file
+}
diff --git a/test_ed25519.c b/test_ed25519.c
index 78c11bc..d921d03 100644
--- a/test_ed25519.c
+++ b/test_ed25519.c
@@ -35,7 +35,7 @@ struct pktest {
 #define SECRETKEYBYTES 64
 #define PUBLICKEYBYTES 32
 
-int main()
+int main(void)
 {
 	u8 seedbuf[SEEDBYTES];
 	u8 secretbuf1[SECRETKEYBYTES];
@@ -63,4 +63,4 @@ int main()
 	}
 	
 	return 0;
-}
\ No newline at end of file
+}