diff --git a/src/jrd/evl.cpp b/src/jrd/evl.cpp
index 74a79fe25e..e3f44fc403 100644
--- a/src/jrd/evl.cpp
+++ b/src/jrd/evl.cpp
@@ -3286,19 +3286,17 @@ static dsc* concatenate(thread_db* tdbb, jrd_nod* node, impure_value* impure)
 		UCHAR* p = impure->vlu_desc.dsc_address;
 
 		if (length1) {
-			do {
-				*p++ = *address1++;
-			} while (--length1);
+			memcpy(p, address1, length1);
+			p += length1;
 		}
 
 		if (length2) {
-			do {
-				*p++ = *address2++;
-			} while (--length2);
+			memcpy(p, address2, length2);
 		}
 
-		if (temp3)
+		if (temp3) {
 			delete temp3;
+		}
 	}
 	return &impure->vlu_desc;
 }
diff --git a/src/jrd/idx.cpp b/src/jrd/idx.cpp
index d5173d38e2..93abf73d4a 100644
--- a/src/jrd/idx.cpp
+++ b/src/jrd/idx.cpp
@@ -399,9 +399,9 @@ void IDX_create_index(
 
 			if (l > 0) {
                 const UCHAR* q = key.key_data;
-				do {
-					*p++ = *q++;
-				} while (--l);
+				memcpy(p, q, l);
+				p += l;
+				q += l;
 			}
 			if ( (l = key_length - key.key_length) ) {
 				do {