diff --git a/src/java.smartcardio/share/native/libj2pcsc/pcsc.c b/src/java.smartcardio/share/native/libj2pcsc/pcsc.c
index 26f91c6cf6b5f..3a6170bb7bf6c 100644
--- a/src/java.smartcardio/share/native/libj2pcsc/pcsc.c
+++ b/src/java.smartcardio/share/native/libj2pcsc/pcsc.c
@@ -45,7 +45,7 @@
 #define dprintf2(s, p1, p2) printf(s, p1, p2)
 #define dprintf3(s, p1, p2, p3) printf(s, p1, p2, p3)
 #else
-#undef dprintf
+#undef dprintf // GNU, POSIX.1-2008
 #define dprintf(s)
 #define dprintf1(s, p1)
 #define dprintf2(s, p1, p2)
diff --git a/src/jdk.crypto.cryptoki/share/native/libj2pkcs11/j2secmod.h b/src/jdk.crypto.cryptoki/share/native/libj2pkcs11/j2secmod.h
index c35bf677f2d09..999d0eaa6291b 100644
--- a/src/jdk.crypto.cryptoki/share/native/libj2pkcs11/j2secmod.h
+++ b/src/jdk.crypto.cryptoki/share/native/libj2pkcs11/j2secmod.h
@@ -42,7 +42,7 @@ void *p11FindFunction(JNIEnv *env, jlong jHandle, const char *functionName);
 #define dprintf2(s, p1, p2) printf(s, p1, p2)
 #define dprintf3(s, p1, p2, p3) printf(s, p1, p2, p3)
 #else
-#undef dprintf
+#undef dprintf // GNU, POSIX.1-2008
 #define dprintf(s)
 #define dprintf1(s, p1)
 #define dprintf2(s, p1, p2)