diff --git a/src/util/arch/x86/bitutils.h b/src/util/arch/x86/bitutils.h
index 4141119a..485b6512 100644
--- a/src/util/arch/x86/bitutils.h
+++ b/src/util/arch/x86/bitutils.h
@@ -285,6 +285,11 @@ static really_inline
 u64a pdep64_impl(u64a x, u64a mask) {
     return _pdep_u64(x, mask);
 }
+#else
+static really_inline
+u64a pdep64_impl(u64a x, u64a mask) {
+    return pdep64_impl_c(x, mask);
+}
 #endif
 
 /* compilers don't reliably synthesize the 32-bit ANDN instruction here,