diff --git a/CMakeLists.txt b/CMakeLists.txt
index d2c96f1252..2b6294b9f4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -296,7 +296,7 @@ if(HAVE_GETPROGNAME)
 	add_definitions(-DHAVE_GETPROGNAME)
 endif()
 
-check_symbol_exists(syslog_r "syslog.h" "stdarg.h" HAVE_SYSLOG_R)
+check_symbol_exists(syslog_r "syslog.h;stdarg.h" HAVE_SYSLOG_R)
 if(HAVE_SYSLOG_R)
 	add_definitions(-DHAVE_SYSLOG_R)
 endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 8f647b1c16..845c23fd20 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -693,7 +693,7 @@ set_tests_properties(shutdowntest PROPERTIES ENVIRONMENT "srcdir=${TEST_SOURCE_D
 # Emscripten does not support socketpair syscall.
 if(NOT (CMAKE_SYSTEM_NAME MATCHES "WindowsStore" OR EMSCRIPTEN))
 	set(SIGNERTEST_SRC signertest.c)
-	check_symbol_exists(pipe2 "fcntl.h unistd.h" HAVE_PIPE2)
+	check_symbol_exists(pipe2 "fcntl.h;unistd.h" HAVE_PIPE2)
 	if(HAVE_PIPE2)
 		add_definitions(-DHAVE_PIPE2)
 	else()
@@ -809,7 +809,7 @@ add_platform_test(tlslegacytest tlslegacytest)
 # Emscripten does not support socketpair syscall.
 if(NOT (CMAKE_SYSTEM_NAME MATCHES "WindowsStore" OR EMSCRIPTEN))
 	set(TLSTEST_SRC tlstest.c)
-	check_symbol_exists(pipe2 "fcntl.h unistd.h" HAVE_PIPE2)
+	check_symbol_exists(pipe2 "fcntl.h;unistd.h" HAVE_PIPE2)
 	if(HAVE_PIPE2)
 		add_definitions(-DHAVE_PIPE2)
 	else()