diff --git a/src/include/86box/plat_fallthrough.h b/src/include/86box/plat_fallthrough.h
index aadd4e14d..6165b266c 100644
--- a/src/include/86box/plat_fallthrough.h
+++ b/src/include/86box/plat_fallthrough.h
@@ -18,6 +18,7 @@
 #ifndef EMU_PLAT_FALLTHROUGH_H
 #define EMU_PLAT_FALLTHROUGH_H
 
+#ifndef EMU_PLAT_H
 #ifdef _MSC_VER
 # define fallthrough do {} while (0) /* fallthrough */
 #else
@@ -30,5 +31,6 @@
 #  define fallthrough do {} while (0) /* fallthrough */
 # endif
 #endif
+#endif
 
 #endif /*EMU_PLAT_FALLTHROUGH_H*/
diff --git a/src/include/86box/plat_unused.h b/src/include/86box/plat_unused.h
index 73eaebaae..226cf677d 100644
--- a/src/include/86box/plat_unused.h
+++ b/src/include/86box/plat_unused.h
@@ -21,11 +21,13 @@
 #ifndef EMU_PLAT_UNUSED_H
 #define EMU_PLAT_UNUSED_H
 
+#ifndef EMU_PLAT_H
 #ifdef _MSC_VER
 #    define UNUSED(arg) arg
 #else
 /* A hack (GCC-specific?) to allow us to ignore unused parameters. */
 #    define UNUSED(arg) __attribute__((unused)) arg
 #endif
+#endif
 
 #endif /*EMU_PLAT_UNUSED_H*/