diff --git a/meson.build b/meson.build
index 30be7e0bd..a62a8a900 100644
--- a/meson.build
+++ b/meson.build
@@ -179,10 +179,8 @@ foreach decl : [
                ]
 
         # We get -1 if the size cannot be determined
-        have = cc.sizeof(decl, prefix : decl_headers, args : '-D_GNU_SOURCE') > 0
-
-	if have == true
-		conf.set10('HAVE_' + decl.underscorify().to_upper(), have)
+        if cc.sizeof(decl, prefix : decl_headers, args : '-D_GNU_SOURCE') > 0
+		conf.set10('HAVE_' + decl.underscorify().to_upper(), true)
 	endif
 endforeach
 
@@ -228,9 +226,8 @@ foreach ident : [
                                #include <sys/resource.h>'''],
 ]
 
-        have = cc.has_function(ident[0], prefix : ident[1], args : '-D_GNU_SOURCE')
-	if have == true
-		conf.set10('HAVE_' + ident[0].to_upper(), have)
+        if cc.has_function(ident[0], prefix : ident[1], args : '-D_GNU_SOURCE')
+		conf.set10('HAVE_' + ident[0].to_upper(), true)
 	endif
 endforeach
 
@@ -259,10 +256,8 @@ if libseccomp.found()
 	               ]
 
 	        # We get -1 if the size cannot be determined
-	        have = cc.sizeof(decl, prefix : seccomp_headers, args : '-D_GNU_SOURCE') > 0
-
-		if have == true
-			conf.set10('HAVE_' + decl.underscorify().to_upper(), have)
+	        if cc.sizeof(decl, prefix : seccomp_headers, args : '-D_GNU_SOURCE') > 0
+			conf.set10('HAVE_' + decl.underscorify().to_upper(), true)
 		endif
 	endforeach
 endif
diff --git a/src/include/meson.build b/src/include/meson.build
index 85292e232..03817c157 100644
--- a/src/include/meson.build
+++ b/src/include/meson.build
@@ -7,7 +7,7 @@ include_sources = files(
 	'netns_ifaddrs.h')
 
 if cc.has_function('getline', prefix : '#include <stdio.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_GETLINE', have)
+	conf.set10('HAVE_GETLINE', true)
 else
 	include_sources += files(
 		'getline.c',
@@ -15,7 +15,7 @@ else
 endif
 
 if cc.has_function('fexecve', prefix : '#include <unistd.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_FEXECVE', have)
+	conf.set10('HAVE_FEXECVE', true)
 else
 	include_sources += files(
 		'fexecve.c',
@@ -29,7 +29,7 @@ getgr_headers = '''
 '''
 
 if cc.has_function('getgrgid_r', prefix : getgr_headers, args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_GETGRGID_R', have)
+	conf.set10('HAVE_GETGRGID_R', true)
 else
 	include_sources += files(
 		'getgrgid_r.c',
@@ -43,17 +43,17 @@ mntent_headers = '''
 
 have_hasmntopt = cc.has_function('hasmntopt', prefix : mntent_headers, args : '-D_GNU_SOURCE')
 if have_hasmntopt
-	conf.set10('HAVE_HASMNTOPT', have)
+	conf.set10('HAVE_HASMNTOPT', true)
 endif
 
 have_setmntent = cc.has_function('setmntent', prefix : mntent_headers, args : '-D_GNU_SOURCE')
 if have_setmntent
-	conf.set10('HAVE_SETMNTENT', have)
+	conf.set10('HAVE_SETMNTENT', true)
 endif
 
 have_endmntent = cc.has_function('endmntent', prefix : mntent_headers, args : '-D_GNU_SOURCE')
 if have_endmntent
-	conf.set10('HAVE_ENDMNTENT', have)
+	conf.set10('HAVE_ENDMNTENT', true)
 endif
 
 if have_hasmntopt == false or have_setmntent == false or have_endmntent == false
@@ -63,7 +63,7 @@ if have_hasmntopt == false or have_setmntent == false or have_endmntent == false
 endif
 
 if cc.has_function('strlcpy', prefix : '#include <string.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_STRLCPY', have)
+	conf.set10('HAVE_STRLCPY', true)
 else
 	include_sources += files(
 		'strlcpy.c',
@@ -71,7 +71,7 @@ else
 endif
 
 if cc.has_function('strlcat', prefix : '#include <string.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_STRLCAT', have)
+	conf.set10('HAVE_STRLCAT', true)
 else
 	include_sources += files(
 		'strlcat.c',
@@ -79,7 +79,7 @@ else
 endif
 
 if cc.has_function('strchrnul', prefix : '#include <string.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_STRCHRNUL', have)
+	conf.set10('HAVE_STRCHRNUL', true)
 else
 	include_sources += files(
 		'strchrnul.c',
@@ -87,7 +87,7 @@ else
 endif
 
 if cc.has_function('openpty', prefix : '#include <pty.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_OPENPTY', have)
+	conf.set10('HAVE_OPENPTY', true)
 else
 	include_sources += files(
 		'openpty.c',
diff --git a/src/lxc/tools/meson.build b/src/lxc/tools/meson.build
index 1e91cdfae..40a131959 100644
--- a/src/lxc/tools/meson.build
+++ b/src/lxc/tools/meson.build
@@ -135,7 +135,7 @@ tools_lxc_console_sources = files(
 	'lxc_console.c') + tools_common_sources
 
 if cc.has_function('getsubopt', prefix : '#include <stdlib.h>', args : '-D_GNU_SOURCE')
-	conf.set10('HAVE_GETSUBOPT', have)
+	conf.set10('HAVE_GETSUBOPT', true)
 else
 	include_sources += files(
 		'tools/include/getsubopt.c',