diff --git a/tests/protocol/instruction_read.c b/tests/protocol/instruction_read.c
index f10e0017..930b5b5e 100644
--- a/tests/protocol/instruction_read.c
+++ b/tests/protocol/instruction_read.c
@@ -55,7 +55,7 @@ void test_instruction_read() {
     }
 
     /* Child (pipe writer) */
-    if (childpid != 0) {
+    if (childpid == 0) {
         close(rfd);
         CU_ASSERT_EQUAL(
             write(wfd, test_string, sizeof(test_string)),
diff --git a/tests/protocol/instruction_write.c b/tests/protocol/instruction_write.c
index 5a21b608..8e12dfc1 100644
--- a/tests/protocol/instruction_write.c
+++ b/tests/protocol/instruction_write.c
@@ -50,7 +50,7 @@ void test_instruction_write() {
     }
 
     /* Child (pipe writer) */
-    if (childpid != 0) {
+    if (childpid == 0) {
 
         guac_socket* socket;
 
diff --git a/tests/protocol/nest_write.c b/tests/protocol/nest_write.c
index 5d4c231e..e1b885b2 100644
--- a/tests/protocol/nest_write.c
+++ b/tests/protocol/nest_write.c
@@ -50,7 +50,7 @@ void test_nest_write() {
     }
 
     /* Child (pipe writer) */
-    if (childpid != 0) {
+    if (childpid == 0) {
 
         guac_socket* nested_socket;
         guac_socket* socket;