diff --git a/package/m4/m4.mk b/package/m4/m4.mk
index 39ad898b10..f5e1e27ad8 100644
--- a/package/m4/m4.mk
+++ b/package/m4/m4.mk
@@ -10,4 +10,14 @@ M4_SITE = $(BR2_GNU_MIRROR)/m4
 M4_LICENSE = GPL-3.0+
 M4_LICENSE_FILES = COPYING
 
+# gcc-15 defaults to -std=gnu23 which is incorrectly detected and
+# generates build failures in the gnulib copy included in
+# m4-1.4.19. We workaround this by forcing the previous gcc default
+# standard, which is -std=gnu17 only when host gcc is >= 15. This
+# workaround can be removed when m4 will be updated to a version
+# including a fix for gcc-15.
+ifeq ($(BR2_HOST_GCC_AT_LEAST_15),y)
+HOST_M4_CONF_ENV = CFLAGS="$(HOST_CFLAGS) -std=gnu17"
+endif
+
 $(eval $(host-autotools-package))