diff --git a/gcc/testsuite/gcc.dg/analyzer/pipe-glibc.c b/gcc/testsuite/gcc.dg/analyzer/pipe-glibc.c
index 60558a870b9d7b93aaa637d6509b7756dfe0e679..fe38ddef3959a1b7589852d21dd7a3c30d599b37 100644
--- a/gcc/testsuite/gcc.dg/analyzer/pipe-glibc.c
+++ b/gcc/testsuite/gcc.dg/analyzer/pipe-glibc.c
@@ -1,6 +1,7 @@
-/* Example of pipe usage from glibc manual.  */
-
 /* { dg-skip-if "" { "avr-*-*" } } */
+/* { dg-require-fork "" } */
+
+/* Example of pipe usage from glibc manual.  */
 
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/gcc/testsuite/gcc.dg/analyzer/pipe-manpages.c b/gcc/testsuite/gcc.dg/analyzer/pipe-manpages.c
index 6b9ae4d260281aa05beac90661f06bca59d0c7be..ac5805fdba092a0a2e8c5dc504ad0b813df766fd 100644
--- a/gcc/testsuite/gcc.dg/analyzer/pipe-manpages.c
+++ b/gcc/testsuite/gcc.dg/analyzer/pipe-manpages.c
@@ -1,3 +1,5 @@
+/* { dg-require-fork "" } */
+
 /* Example of "pipe" from release 5.13 of the Linux man-pages project.
 
 Copyright (C) 2005, 2008, Michael Kerrisk <mtk.manpages@gmail.com>