diff --git a/src/jrd/SysFunction.cpp b/src/jrd/SysFunction.cpp
index e46db6e8ee..0088dfc0c0 100644
--- a/src/jrd/SysFunction.cpp
+++ b/src/jrd/SysFunction.cpp
@@ -2802,9 +2802,10 @@ dsc* evlDateAdd(thread_db* tdbb, const SysFunction* function, const NestValueArr
 					ERR_post(Arg::Gds(rangeExceededStatus));
 
 				tm times;
-				timestamp.decode(&times);
+				int fractions;
+				timestamp.decode(&times, &fractions);
 				times.tm_year += quantity;
-				timestamp.encode(&times);
+				timestamp.encode(&times, fractions);
 
 				int day = times.tm_mday;
 				timestamp.decode(&times);
@@ -2820,7 +2821,8 @@ dsc* evlDateAdd(thread_db* tdbb, const SysFunction* function, const NestValueArr
 					ERR_post(Arg::Gds(rangeExceededStatus));
 
 				tm times;
-				timestamp.decode(&times);
+				int fractions;
+				timestamp.decode(&times, &fractions);
 
 				int md[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
@@ -2855,7 +2857,7 @@ dsc* evlDateAdd(thread_db* tdbb, const SysFunction* function, const NestValueArr
 				else if (times.tm_mday < 1)
 					times.tm_mday = 1;
 
-				timestamp.encode(&times);
+				timestamp.encode(&times, fractions);
 			}
 			break;