diff --git a/common/quic.c b/common/quic.c
index 5a41399..ca7ffd2 100644
--- a/common/quic.c
+++ b/common/quic.c
@@ -251,7 +251,7 @@ static const unsigned int tabrand_chaos[TABRAND_TABSIZE] = {
     0x81474925, 0xa8b6c7ad, 0xee5931de, 0xb2f8158d, 0x59fb7409, 0x2e3dfaed, 0x9af25a3f, 0xe1fed4d5,
 };
 
-static unsigned int stabrand()
+static unsigned int stabrand(void)
 {
     //ASSERT( !(TABRAND_SEEDMASK & TABRAND_TABSIZE));
     //ASSERT( TABRAND_SEEDMASK + 1 == TABRAND_TABSIZE );
@@ -535,7 +535,7 @@ static int J[MELCSTATES] = {
 };
 
 /* creates the bit counting look-up table. */
-static void init_zeroLUT()
+static void init_zeroLUT(void)
 {
     int i, j, k, l;
 
diff --git a/common/rop3.c b/common/rop3.c
index af872c1..12d9f11 100644
--- a/common/rop3.c
+++ b/common/rop3.c
@@ -31,7 +31,7 @@ typedef void (*rop3_with_pattern_handler_t)(pixman_image_t *d, pixman_image_t *s
 typedef void (*rop3_with_color_handler_t)(pixman_image_t *d, pixman_image_t *s,
                                           SpicePoint *src_pos, uint32_t rgb);
 
-typedef void (*rop3_test_handler_t)();
+typedef void (*rop3_test_handler_t)(void);
 
 #define ROP3_NUM_OPS 256
 
@@ -56,7 +56,7 @@ static void default_rop3_withe_color_handler(pixman_image_t *d, pixman_image_t *
     WARN("not implemented");
 }
 
-static void default_rop3_test_handler()
+static void default_rop3_test_handler(void)
 {
 }
 
@@ -127,7 +127,7 @@ static void rop3_handle_c##depth##_##name(pixman_image_t *d, pixman_image_t *s,
     }                                                                                           \
 }                                                                                               \
                                                                                                 \
-static void rop3_test##depth##_##name()                                                         \
+static void rop3_test##depth##_##name(void)                                                     \
 {                                                                                               \
     uint8_t d = 0xaa;                                                                           \
     uint8_t s = 0xcc;                                                                           \