diff --git a/config.h b/config.h
index 38a61da4..3d721e87 100644
--- a/config.h
+++ b/config.h
@@ -655,8 +655,9 @@ NAMESPACE_END
 // not provide an ARM implementation. The Cryptogams implementation
 // is about 2x faster than C/C++. Define this to use the Cryptogams
 // AES implementation on GNU Linux systems. When defined, Crypto++
-// will use aes-armv4.S.
-#if !defined(CRYPTOPP_DISABLE_ASM) && defined(__GNUC__) && defined(__arm__)
+// will use aes-armv4.S. LLVM miscomiles aes-armv4.S so disable
+// under Clang. See https://bugs.llvm.org/show_bug.cgi?id=38133.
+#if !defined(CRYPTOPP_DISABLE_ASM) && defined(__arm__) && defined(__GNUC__) && !defined(__clang__)
 # define CRYPTOGAMS_ARM_AES 1
 #endif