diff --git a/.gitignore b/.gitignore
index d3ddf440..8d291285 100644
--- a/.gitignore
+++ b/.gitignore
@@ -137,6 +137,7 @@ sysenter_hook_x86
 test_tb_x86
 test_multihook
 test_pc_change
+mem_fuzz
 
 
 #################
diff --git a/tests/regress/mem_fuzz.c b/tests/regress/mem_fuzz.c
index a1e080cf..aee3cdb0 100644
--- a/tests/regress/mem_fuzz.c
+++ b/tests/regress/mem_fuzz.c
@@ -44,14 +44,14 @@ uint64_t get_aligned_len(){
 void perform_map_step(uc_engine *uc){
     uint64_t addr = get_aligned_addr();
     uint64_t len = get_aligned_len();
-    printf("map(0x%lx,0x%lx); //%d\n", addr, len, step);
+    printf("map(0x%"PRIx64",0x%"PRIx64"); //%d\n", addr, len, step);
     uc_mem_map(uc, addr, len, UC_PROT_READ | UC_PROT_WRITE);
 }
 
 void perform_unmap_step(uc_engine *uc){
     uint64_t addr = get_aligned_addr();
     uint64_t len = get_aligned_len();
-    printf("unmap(0x%lx,0x%lx); //%d\n", addr, len, step);
+    printf("unmap(0x%"PRIx64",0x%"PRIx64"); //%d\n", addr, len, step);
     uc_mem_unmap(uc, addr, len);
 }
 
@@ -60,7 +60,7 @@ void perform_write_step(uc_engine *uc){
     memset(buff, 0, 4096*4);
     uint64_t addr = get_addr();
     uint64_t len = get_len()%(4096*3);
-    printf("write(0x%lx,0x%lx); //%d\n", addr, len, step);
+    printf("write(0x%"PRIx64",0x%"PRIx64"); //%d\n", addr, len, step);
     uc_mem_write(uc, addr, buff, len);
 }
 
@@ -68,7 +68,7 @@ void perform_read_step(uc_engine *uc){
     char* buff[4096*4];
     uint64_t addr = get_addr();
     uint64_t len = get_len()%(4096*3);
-    printf("read(0x%lx,0x%lx); //%d\n", addr, len, step);
+    printf("read(0x%"PRIx64",0x%"PRIx64"); //%d\n", addr, len, step);
     uc_mem_read(uc, addr, buff, len);
 }