diff --git a/c/cards.c b/c/cards.c
index a0de03d..4a4163c 100644
--- a/c/cards.c
+++ b/c/cards.c
@@ -59,5 +59,5 @@ int main(void) {
   printf("Hello bostinha: " _S(1) "\n");
   printf("Cagalhao: " __S(CAGALHAO) "\n");
   printf("Cagalhao: " _S(CAGALHAO) "\n");
-  printf("Size array: %d", sizeof(pontos) / sizeof(pontos[0]));
+  printf("Size array: %ld", sizeof(pontos) / sizeof(pontos[0]));
 }
diff --git a/c/forkhandler.c b/c/forkhandler.c
index 44c1931..1977aae 100644
--- a/c/forkhandler.c
+++ b/c/forkhandler.c
@@ -1,3 +1,6 @@
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-function-declaration"
+
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,3 +23,5 @@ int main() {
   }
   return 0;
 }
+
+#pragma GCC diagnostic pop
diff --git a/c/pthreadex1.c b/c/pthreadex1.c
index c73bdfc..41705b5 100644
--- a/c/pthreadex1.c
+++ b/c/pthreadex1.c
@@ -1,3 +1,5 @@
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-function-declaration"
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -19,3 +21,5 @@ int main() {
   }
   return 0;
 }
+
+#pragma GCC diagnostic pop
diff --git a/c/pthreadex4.c b/c/pthreadex4.c
index 7c17efe..dff1ce8 100644
--- a/c/pthreadex4.c
+++ b/c/pthreadex4.c
@@ -1,3 +1,6 @@
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-function-declaration"
+
 #include <pthread.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -27,3 +30,5 @@ int main() {
   printf("Hello from the main thread!\n");
   return 0;
 }
+
+#pragma GCC diagnostic pop
diff --git a/c/pthreadex5.c b/c/pthreadex5.c
index 6dfd7eb..4c4411c 100644
--- a/c/pthreadex5.c
+++ b/c/pthreadex5.c
@@ -1,3 +1,6 @@
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-function-declaration"
+
 #include <errno.h>
 #include <pthread.h>
 #include <stdio.h>
@@ -40,3 +43,5 @@ int main() {
 
   return 0;
 }
+
+#pragma GCC diagnostic pop